Need help with TWRP Device Tree /data decryption - Android Q&A, Help & Troubleshooting

I am currently developing a twrp device tree for the Gigaset GS4.
GitHub - StarMiner99/android_device_Gigaset_Gigaset_GS4_twrp: TWRP Device Tree for Gigaset GS4
TWRP Device Tree for Gigaset GS4. Contribute to StarMiner99/android_device_Gigaset_Gigaset_GS4_twrp development by creating an account on GitHub.
github.com
Everything is working so far but there is one major problem.
The Data Directory is unreadable:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
This is probably due to encryption.
Things i figured out:
- the device has a metadata partition
- the device uses file base encryption
- twrp does not ask for a password
This is the output of twrp decrypt:
Gigaset_GS4:/ # twrp decrypt twrptest
Attempting to decrypt data partition or user data via command line.
Failed to decrypt data.
Gigaset_GS4:/ #
General information:
- build using twrp-10.0 twrp-minimal-manifest
- stock rom: android 10
- chipset: mt6771
Help would be appreciated!