I have an encrypted android running LineageOS 15. When it said that there was an OTA update, I choose to download and install this new update. In the first moment it seemed to be alright but when the phone restarted itself the recovery (TWRP) appeared again... and again...
It is in a bootloop mode and there is nothing I can do without loss my data and I can't do nothing to copy my date due to the full disk encryption.
The encryption was made, I think, with the fingerprint and even if it was done with a password I cannot decrypt the entire disk (with the command
adb shell twrp decrypt) because my TWRP version doesn't support the decryption.