Hi, I just bought the verizon lg g3 for a use on at&t because I heard that it was unlocked (http://forum.xda-developers.com/verizon-lg-g3/help/unlocked-t2860916). I just went to at&t store to find out that this phone is infact not unlocked. So i would like to know if I can unlock this phone.
It is unlocked in fact and you can install an AT&T sim chip in it, add the correct APN entry and other settings, restart, and use the phone on AT&T. You will usually get a 4gLTE data connection too, depending on what bands AT&T use locally.
I know, because I have done this on AT&T, Cricket, and T-Mobile prepaid.
What he probably meant is that the boot loader is locked so there is currently no way to install alternate firmwares. This is still true, sadly, because Verizon are a bunch of control freaks. We do have rooting methods though.
Sent from my VS985 4G using Tapatalk
can you help me with the settings? I set the apn and it still doesn't recognize the sim. It says this sim does not support this network type when i get search automatically
Change your network type then. Its probably still set on the Verizon one that includes cdma. Change to one that mentions GSM and LTE or just pick global.
You will always have an annoying "sim is weird" icon in the notification bar, but it means nothing.
Sent from my VS985 4G using Tapatalk
Still nothing :/
Sent from my VS985 4G using XDA Free mobile app
Don't worry, you don't have you APN settings right yet. You will need to get the correct settings for your AT&T SIM, edit them in, save...I don't have your settings because I use Cricket or Gophone which are AT&T prepaid. Don't forget to reboot after you get it set up right!
Sent from my VS985 4G using Tapatalk
trent999 said:
Don't worry, you don't have you APN settings right yet. You will need to get the correct settings for your AT&T SIM, edit them in, save...I don't have your settings because I use Cricket or Gophone which are AT&T prepaid. Don't forget to reboot after you get it set up right!
Sent from my VS985 4G using Tapatalk
Click to expand...
Click to collapse
can I get the go phone apn? im trying to get go phone to work not the actual carrier
Yes it will work on the AT&T network, the only detail is that you might probably need to edit the APN's on the device so you can enjoy the LTE, you can get the APN's with any Customer service rep by dialing 8009019878
Sent from my VS985 4G using Tapatalk
Related
I was curious because I heard that the Droid Incredible 4G has a GSM radio in it so I did an experiment. I used a T-mobile micro SIM. I used the 4GLTE switch app for the Thunderbolt to access the hidden menu and I changed the radio mode to one that included GSM/W-CDMA. I popped in my T-mobile SIM and, presto, I got a T-mobile signal. I tested and I was able to make and receive calls and text messages. I had to manually set the APN for data to epc.tmobile.com and now I have EDGE data. I am sure an AT&T Sim will get HSPA+. The GSM appears unlocked now but hard to access. I am afraid, however, that once Verizon releases the update to make GSM roaming available, that it will be locked. Anyway, for now, you can pop in a GSM SIM and use your phone native.
Brooose said:
I was curious because I heard that the Droid Incredible 4G has a GSM radio in it so I did an experiment. I used a T-mobile micro SIM. I used the 4GLTE switch app for the Thunderbolt to access the hidden menu and I changed the radio mode to one that included GSM/W-CDMA. I popped in my T-mobile SIM and, presto, I got a T-mobile signal. I tested and I was able to make and receive calls and text messages. I had to manually set the APN for data to epc.tmobile.com and now I have EDGE data. I am sure an AT&T Sim will get HSPA+. The GSM appears unlocked now but hard to access. I am afraid, however, that once Verizon releases the update to make GSM roaming available, that it will be locked. Anyway, for now, you can pop in a GSM SIM and use your phone native.
Click to expand...
Click to collapse
if its like verizon other global settings (inc2) you can request the unlock code from them (they ll give you crap about using their intl plans first, but just yell until someone does it)
Brooose said:
I was curious because I heard that the Droid Incredible 4G has a GSM radio in it so I did an experiment. I used a T-mobile micro SIM. I used the 4GLTE switch app for the Thunderbolt to access the hidden menu and I changed the radio mode to one that included GSM/W-CDMA. I popped in my T-mobile SIM and, presto, I got a T-mobile signal. I tested and I was able to make and receive calls and text messages. I had to manually set the APN for data to epc.tmobile.com and now I have EDGE data. I am sure an AT&T Sim will get HSPA+. The GSM appears unlocked now but hard to access. I am afraid, however, that once Verizon releases the update to make GSM roaming available, that it will be locked. Anyway, for now, you can pop in a GSM SIM and use your phone native.
Click to expand...
Click to collapse
Very nice info there Broose. Thanks for taking the time to try it.
Brooose said:
I was curious because I heard that the Droid Incredible 4G has a GSM radio in it so I did an experiment. I used a T-mobile micro SIM. I used the 4GLTE switch app for the Thunderbolt to access the hidden menu and I changed the radio mode to one that included GSM/W-CDMA. I popped in my T-mobile SIM and, presto, I got a T-mobile signal. I tested and I was able to make and receive calls and text messages. I had to manually set the APN for data to epc.tmobile.com and now I have EDGE data. I am sure an AT&T Sim will get HSPA+. The GSM appears unlocked now but hard to access. I am afraid, however, that once Verizon releases the update to make GSM roaming available, that it will be locked. Anyway, for now, you can pop in a GSM SIM and use your phone native.
Click to expand...
Click to collapse
Works on AT&T with EDGE data as well. I haven't gotten HSPA (any variant) or AT&T LTE working, and I can't play with it too much because it's not my SIM
ATT LTE won't work because the frequencies are different from Verizon but I am surprised that HSPA didn't work. Did you use a setting that included W-CDMA? GSM only would likely mean Edge only.
Sent from my ADR6410LVW using xda premium
Can you link the app you used that worked?
No problems switching back?
https://play.google.com/store/apps/details?id=net.andirc.lteonfoff
from my ADR6410LVW using xda premium
Im afraid I cant get this to work. Does it require a rooted phone?
I have the app, I have a T Mobile micro sim installed. I click on the drop down menu (within the app) and choose the first menu item "Select radio band" and pick PCS (1900-MHz Band) and I get a "successful" prompt afterwards (only when the Tmo sim is installed btw).
I am unable to choose "GSM Only & GSM auto (PRL)" menu choices. Is this normal? I am able to choose GSM/WCDMA/LTE auto though. I dont get any sim error messages, but the phone never seems to want to camp on any GSM network.
You are looking in the wrong place. You need the drop down menu that includes GSM, W-CDMA, EVDO, LTE in various combinations. Select one with GSM in it. Also, I found that you need to have your Verizon SIM in first and then hot swap it with the t-mobile sim.
On the Rezound if you make a couple build.prop tweaks it fixes texting and data on GSM.
Brooose said:
You are looking in the wrong place. You need the drop down menu that includes GSM, W-CDMA, EVDO, LTE in various combinations. Select one with GSM in it. Also, I found that you need to have your Verizon SIM in first and then hot swap it with the t-mobile sim.
Click to expand...
Click to collapse
No, I was in the right place to begin with, I just thought it would be able to pick just gsm but it wont.
And you left out that piece of informationin bold, but still not working...
Can you give us your firmware & radio version, perhaps some phones have been updated to block this.
Anyone have any luck with this?
OP, is your phone stock? Rooted?
What if it has a bad ESN will this work or a way to make gsm work even with a bad ESN I'm asking because if Verizon does not have droid 3 s I will get this phone then go with at&t but will like to know if I can change the radio so I can so this
Sent from my Galaxy Nexus using xda app-developers app
One additional thing I found was that I got it to work by hot swapping the Sims. It seems like the Verizon sim has to be in when the phone boots. Once it boots, use Phone Info to change the mode to GSM and then switch your sim.
Sent from my SGH-I535 using xda premium
Brooose said:
One additional thing I found was that I got it to work by hot swapping the Sims. It seems like the Verizon sim has to be in when the phone boots. Once it boots, use Phone Info to change the mode to GSM and then switch your sim.
Sent from my SGH-I535 using xda premium
Click to expand...
Click to collapse
So your saying this works on a bad ESN one?
Sent from my Galaxy Nexus using xda app-developers app
leerpsp said:
What if it has a bad ESN will this work or a way to make gsm work even with a bad ESN I'm asking because if Verizon does not have droid 3 s I will get this phone then go with at&t but will like to know if I can change the radio so I can so this
Sent from my Galaxy Nexus using xda app-developers app
Click to expand...
Click to collapse
I would think it should work. The ESN is used for the CDMA networks, the IMEI is used for GSM. Stick with GSM and you should be ok...
Dinc 4G now Global Ready
I was just chatting with a VZ rep online and was told that Verizon has already released a software update, thus making Dinc 4G officially global ready. Can anyone confirm/deny?
I asked her for a software version number which enables this, but she wasn't able to provide it.
Pete7874 said:
I was just chatting with a VZ rep online and was told that Verizon has already released a software update, thus making Dinc 4G officially global ready. Can anyone confirm/deny?
I asked her for a software version number which enables this, but she wasn't able to provide it.
Click to expand...
Click to collapse
Deny. No update has come out so far. You would be able to read about here if it had come out.
JDMpire said:
I would think it should work. The ESN is used for the CDMA networks, the IMEI is used for GSM. Stick with GSM and you should be ok...
Click to expand...
Click to collapse
Thanks I think I will go buy one cheep forum ebay
Sent from my Galaxy Nexus using xda app-developers app
Hopefully no one has posted this before me.
Many of you must have, at one point tried to put an AT&T 3 G SIM into a 4G LTE phone. Of course, you would then see that calling and texting worked, but no data!
Well, here is a simple method to enable data. Go to your APN settings and add wap.cingular for the APN. Cyanogenmod will already have that APN in there under the name ATT, but most stock ROMs don't. The name can be whatever you like.
Sent from my SGH-I897 using XDA
I've searched quite a bit and I saw a few threads that said that the Verizon GS4 comes sim unlocked. But I put in a friends Sprint Sim and I got an error message that said "non verizon sim." I also saw tutorials on how to go into the phones menu by typing *#06# or *#0011# but these do not work on my phone. Is there a code that will work on my phone? Also, do I have to install a custom ROM on this phone to get the sim unlocked? I really don't want to go that route but if I have to I will.
Sprint SIM probably isn't compatible. Try a GSM carrier SIM.
I tried the T-mobile version Straight Talk card and it says the same. "non-verizon SIM"
OK. I found out that you have to enable the hidden menus first. There is a forum here that talks about it. It's titled [how to] Enable Hidden Menus for Verizon Galaxy S4. And from there you can sim unlock.
I've seen reports that people where getting non- verizon sim message but phone still worked on other carriers.
This is true. I have put in an active ATT sim got "non-Verizon SIM" message and could still make calls and Internet from the ATT SIM.
Sent from my SCH-I545 using Tapatalk 4 Beta
Silentgray said:
This is true. I have put in an act ve ATT sim got "non-Verizon SIM" message and could still make calls and Internet from the ATT SIM.
Sent from my SCH-I545 using Tapatalk 4 Beta
Click to expand...
Click to collapse
I put a China cdma card,it can make calls and send message,but Internet over evdo（3g） can not work.
I don't know how to set.
meiyijun001 said:
I put a China cdma card,it can make calls and send message,but Internet over evdo（3g） can not work.
I don't know how to set.
Click to expand...
Click to collapse
This is only works with gsm. The cdma side is still locked unless you call Verizon and get them to unlock it.
Sent from my SCH-I545 using Tapatalk 4 Beta
I am currently in China and trying to get my sch-i545 to work with a sim card I purchased. While my phone is able to recognize that the sim card is there I recieve the message that the sim card is from an unknown source. Is there any way to fix this with the sch-i545 even though it is not the international version of the phone.
wilcoxky said:
I am currently in China and trying to get my sch-i545 to work with a sim card I purchased. While my phone is able to recognize that the sim card is there I recieve the message that the sim card is from an unknown source. Is there any way to fix this with the sch-i545 even though it is not the international version of the phone.
Click to expand...
Click to collapse
Are you rooted? Are you running a custom ROM?
Silentgray said:
This is only works with gsm. The cdma side is still locked unless you call Verizon and get them to unlock it.
Sent from my SCH-I545 using Tapatalk 4 Beta
Click to expand...
Click to collapse
Are they capable of doing this with the S4? Assuming they are, are you speaking theoretically or with certainty? Could you confirm via experience or perhaps cite the information?
Reason I'm asking I tried to use a non-Verizon sim once with limited success on an S3. Called Verizon to see if it was a sim-lock related issue and they insisted that the phone shipped as unlocked as could possibly be, which would contradict your statement assuming the same holds true for the S4.
Sent from my SCH-I545 using xda app-developers app
zerofighter1 said:
Are they capable of doing this with the S4? Assuming they are, are you speaking theoretically or with certainty? Could you confirm via experience or perhaps cite the information?
Reason I'm asking I tried to use a non-Verizon sim once with limited success on an S3. Called Verizon to see if it was a sim-lock related issue and they insisted that the phone shipped as unlocked as could possibly be, which would contradict your statement assuming the same holds true for the S4.
Sent from my SCH-I545 using xda app-developers app
Click to expand...
Click to collapse
I have put an AT&T sim in my S4, added the correct APN info and I wa getting data and could make calls.
Sent from my SCH-I545 using Tapatalk 4 Beta
Silentgray said:
I have put an AT&T sim in my S4, added the correct APN info and I wa getting data and could make calls.
Sent from my SCH-I545 using Tapatalk 4 Beta
Click to expand...
Click to collapse
That's interesting, but doesn't answer my question - that being about Verizon being able to unlock the S4 for CDMA carriers. I'm aware that it's GSM unlocked.
Sent from my SCH-I545 using xda app-developers app
zerofighter1 said:
That's interesting, but doesn't answer my question - that being about Verizon being able to unlock the S4 for CDMA carriers. I'm aware that it's GSM unlocked.
Sent from my SCH-I545 using xda app-developers app
Click to expand...
Click to collapse
Sorry I misunderstood. Don't mention sim unlock to them since the cdma doesn't use the sim. There is another thread floating around here that mentioned this but I couldn't find it. What it boiled dien to was telling that you are traveling overseas and would like them to unlock cdma. This doesn't Guarantee that they will. Sorry I couldn't find the link.
Sent from my SCH-I545 using Tapatalk 4 Beta
Anyone ever call Verizon and had their s4 or S3 unlocked thru them before who finished their contract? If so can you explain what the process was they walked you thru?
I popped in a tmobile sim in my vzw s4 and it worked without any mids. It just says unknown sim but it works
Sent from my SCH-I545 using xda app-developers app
Actually it's quite easy to do. You go on your My Verizon account, or call them and add the $4.99 international package. That does NOT include any data, only the capability to use it on CDMA elsewhere or the Global option on your Verizon Sim.
I recently traveled to Sweden and have used several different Verizon phones (with International SIM) outside the USA and not had issues.
The "Non-Verizon" sim message has absolutely no bearing on being able to use another sim in the phone, its UNLOCKED. If it's a GSM simcard voice will work no problem, data you have to add APN in. You cannot use a Sprint SIM because like Verizon they use authentication by way of ESN or IMEI to be registered on their CDMA network. So it just won't authenticate.
So you don't need to SIM unlock, it's already unlocked.
I tried L720 unlock mode, failed
oc3rulz said:
Actually it's quite easy to do. You go on your My Verizon account, or call them and add the $4.99 international package. That does NOT include any data, only the capability to use it on CDMA elsewhere or the Global option on your Verizon Sim.
I recently traveled to Sweden and have used several different Verizon phones (with International SIM) outside the USA and not had issues.
The "Non-Verizon" sim message has absolutely no bearing on being able to use another sim in the phone, its UNLOCKED. If it's a GSM simcard voice will work no problem, data you have to add APN in. You cannot use a Sprint SIM because like Verizon they use authentication by way of ESN or IMEI to be registered on their CDMA network. So it just won't authenticate.
So you don't need to SIM unlock, it's already unlocked.
Click to expand...
Click to collapse
Adding this feature does not cost anything on my unlimited plan. Only if you want to add additional global data and voice rate plans does it cost to enable the feature.
OK so in that case how do we get 3g and higher speeds when using other Sims? I took mine too ATT they put in the sim and still wouldn't get more then Edge data, We also have a Ver S3 that we have on ST prepay and put in the APNS and we still can't get above edge data either. Here the thing, the s4 is global ready yet it still has some kind of lock to prevent data so has anyone ever contacted Verizon after theit contract to come about unlocking their device to use on other carriers? What is the point of buying these phones, if they won't unlock then for us after contact is up? It would still be there phone, seems were just leasing it cause we can't take it with us to another carrier. Any guide to get these unlocked for3g and data please?!!
I have a LG G3 verizon with bad ESN i ve heard that comes gsm factory unlock and can insert a tmobile or a&tt sim card, i just put a Tmobile sim card and doesnt read it what can i do to fix this and the phone be able to read any sim card? actually have a LG G2 verizon and is working with Tmobile sim card please help me thanks
Did you change the network setting?
spotmark said:
Did you change the network setting?
Click to expand...
Click to collapse
YES i did and nothing i changed network mode to lte/ gsm/umts
Cesaremopar said:
YES i did and nothing i changed network mode to lte/ gsm/umts
Click to expand...
Click to collapse
Did you change APN settings?
318sugarhill said:
Did you change APN settings?
Click to expand...
Click to collapse
Yes i did and nothing, do you think is for the bad esn with verizon? or that doesn't matter if I use it with any other GSM sim card
That should only matter for Verizon I believe
If memory recalls, GSM is only for overseas. I believe it's locked down for USA for the v985.
Im not sure how that court ruling for unlocked smartphone effects the v985 so I don't know if its unlocked.
Sent from my VZW LG G3 (tapatalk)
RHChan84 said:
If memory recalls, GSM is only for overseas. I believe it's locked down for USA for the v985.
Im not sure how that court ruling for unlocked smartphone effects the v985 so I don't know if its unlocked.
Sent from my VZW LG G3 (tapatalk)
Click to expand...
Click to collapse
So if mine its verizon locked with bad esn can't be used with any GSM carrier inside USA just can be used with gsm for overseas?
RHChan84 said:
If memory recalls, GSM is only for overseas. I believe it's locked down for USA for the v985.
Im not sure how that court ruling for unlocked smartphone effects the v985 so I don't know if its unlocked.
Sent from my VZW LG G3 (tapatalk)
Click to expand...
Click to collapse
No... I don't believe this is correct. For verizon to be able to use the computer block spectrum... Their 4g devices are required to be sim unlocked. They can be used for us carriers... As long as it has the proper radios.
Sent from my VS985 4G using XDA Free mobile app
My Verizon vs985 works on both Cricket and T-Mobile pre-paid Sims once I have installed the right APNs and switched modes. You must reboot after setting the APN. It works in the USA as well as outside, given radio frequency compatibility. I even get LTE on band4, where available.
Sent from my VS985 4G using Tapatalk
I just got the VS985 and popped in my ST AT&T SIM. I did have to enter the ST apn but I left the network mode at global and everything works: voice, data (LTE), mms. I applied the hotspot mod and that works too. :good:
joarce said:
I just got the VS985 and popped in my ST AT&T SIM. I did have to enter the ST apn but I left the network mode at global and everything works: voice, data (LTE), mms. I applied the hotspot mod and that works too. :good:
Click to expand...
Click to collapse
Good to know since I am switching to AT&T :good:
He has a phone with a "BAD ESN".
If it has been blacklisted there is nothing he can do.
I quite frankly won't help a person with a phone with a "BAD ESN".
He either got ripped off, bought a device cheap that was reported stolen, etc or he stole it.
In any case I'm pretty sure it violates the terms of this site to help someone with a less than legally acquired phone.
It's a brick or a good wifi device.
BAD ESN (MEID) can be reported across carriers and will not be able to be activated anywhere in the US.
I never really knew what a bad esn was other than you couldn't activate it on Verizon. I always thought it was someone who didn't pay their bill or something. Didn't know it meant stolen phone. Thanks for the heads up.
Sent from my VS985 4G using XDA Free mobile app
318sugarhill said:
I never really knew what a bad esn was other than you couldn't activate it on Verizon. I always thought it was someone who didn't pay their bill or something. Didn't know it meant stolen phone. Thanks for the heads up.
Sent from my VS985 4G using XDA Free mobile app
Click to expand...
Click to collapse
Bad ESN can be flagged due to a number of things:
1. Bill not paid while under contract => They own the phone so they blacklist it.
2. Broken contract with device not returned => They own the phone so they blacklist it.
3. Insurance claim filed => Phone should be returned to provider, if not blacklisted.
4. Lost or stolen
There may be others, but the gist is the phone has a shady past if the ESN is bad.
No help.
same situation here, is the APN setting automatic? I am on cm13 with 35b bootstack
can phone with bad ESN be banned overseas too ????
---------- Post added at 07:02 PM ---------- Previous post was at 06:57 PM ----------
so it will work with gsm carrier overseas ???
Hi, I have an LG V10 that I purchased from TMOBILE. I switched to AT&T, and brought my T-Mobile device with me. Everything works fine, but I cannot get 4G LTE service at all. I have tried 2 APN settings, and that does not help. I live in a large metropolitan area, and I know that 4G is available here with AT&T. Does anybody have any idea why I can only get 4G and not 4G LTE?
Thanks!
This happened to me when flashing a custom Rom, the fix for me was to change the network speed to 3g or 2g then keep changing Ap's until you see you are connected to a network. Once you see that you are connected, change it back to 4gLTE. Let me know if this worked for you.
This is the APN I use and got LTE to work. It's old APN but it works for me.
Name-LTE
APN-phone
proxy, port, username, password-Not set
MMSC-http://mmsc.mobile.att.net
MMS proxy-proxy.mobile.att.net
MMS port-8080 (In order for MMS to work with adblock plus, I use 8080 instead of 80 because using port 80 will cause the MMS not to work)
MCC-310
MNC-410
Authentication type-Not set
APN type-default,mms,supl,hipri (hipri is what makes LTE to work. Without using "hipri" I only get 4G, not LTE. No need to use "fota". It is for tablets)
APN protocol-IPv4
If changing to this APN setting and you still don't get LTE, reboot the phone.
bkgibby said:
This happened to me when flashing a custom Rom, the fix for me was to change the network speed to 3g or 2g then keep changing Ap's until you see you are connected to a network. Once you see that you are connected, change it back to 4gLTE. Let me know if this worked for you.
Click to expand...
Click to collapse
Wow, i was thinking i was the only one with this wierd problem, i had a lg g3 tmobile with this issue, when i was on wifi for large periods and the back to data, the 4g lte appears like it was working fine, but it never gave me access to inteternet, then i had to revert to 3g or 2g, and when it connects and works, i revert back to 4g lte and works fine, until i get wifi, and the same all over again, but this only happen to me with lg on tmobile, i had htc, samsung and this problem does not seems to happens with that brands, so i tougth it was the lg g3 itself and i sell it, but now i get a brand new v10 with tmobile and the problem is still the same, and i don´t find anything on the internet about it, until i see this post, do you know why is this happen? im on mexico, and i use my phones whit telcel
Have you tried apn unlcok?
Diag 277634#*# and look for the "APN UNLOCK" option
jkyoho said:
Have you tried apn unlcok?
Diag 277634#*# and look for the "APN UNLOCK" option
Click to expand...
Click to collapse
when i hit the apn unlock option appears a message that tells me: "apn has been unlocked" or something like that, but the phone stills the same, do i have to do something else besides manually enter apn settings from my operator?
A word of advice I have an unlocked t-mobile lg v10 and I have had the same issue as you and believe me I tried every possible fix and nothing worked until I tried this fix ( put your sim card in another AT&T device in my case my girlfriend has an AT&T iphone 6 and leave it for a minute or 2 once you see the 4G LTE on that device remove it and put it back into your phone and you will have the 4G LTE all the time, of course you need to set up your apn but like I said I spent a whole month and tried everything before I came to that fix because nothing else worked) I hope that would help you.
I totally switched iphone 6 SIM on unlocked LG v10 ,,,but i saw LTE for 5sec and then back to 4G ...
Don't know if it will work ..
Just a network access problem, you should save yourself some time and just.... Call AT&T customer support?
Or hit the AT&T V10 forums for correct APNs. I'm sure you aren't the first person to deal with this issue.
Yes u can have 4G LTE ...just activate with a AT&T 4G LTE IMEI
missexe10 said:
Hi, I have an LG V10 that I purchased from TMOBILE. I switched to AT&T, and brought my T-Mobile device with me. Everything works fine, but I cannot get 4G LTE service at all. I have tried 2 APN settings, and that does not help. I live in a large metropolitan area, and I know that 4G is available here with AT&T. Does anybody have any idea why I can only get 4G and not 4G LTE?
Thanks!
Click to expand...
Click to collapse
i have the same senario...recently moved to AT&T with the UNLOCKED Tmobile LG V10 and every thing works just fine with AT&T SIM except no 4G LTE and when you asked At&T they will try to convince you to buy their device to get 4G LTE signal....it took me a while to figure it out that u can get 4G LTE on an unlocked LG V10 if u activate the service with any AT&T 4G LTE capable device IMEI..... One more thing.. u are on your own to provide the LTE capable IMEI to customer service. That means don't except to walk in to AT&T store and borrow the IMEI from their display unit..coz they wont let u do that.....
The T-mobile phones pick up perfectly on ATT, it's most likely an APN related issue.