I have a shieldtablet which was working fine, until I decided to encrypt the drive. The process completed, the device rebooted, and it's stuck in a reboot loop. Neither Linux/Windows recognize it when the USB is connected, and it's not listed/identified via the adb or fastboot utilities. I can enter TWRP recovery and the bootloader (nvboot), but it doesn't look like I can push any files to the tablet or flash.
edit: Fortunately the tablet accepts the sdcard, and it looks like I am able to install files via TWRP. I did attempt to format and install LineageOS 16 through it, but the issue remains (lineageos boot animation plays for 1-2 minutes, then the device reboots).
Potentially critical info: When I enter the bootloader, nvtboot versions shows a single glyph (garbage) character (although the bootloader reports version 4.00.2016.04-8b2413b7). Is it possible that the encryption broke the bootloader or some other important partition/data?
Do you have any ideas for further debugging so that I can salvage the tablet?