Hello,
I freshly installed your Lineage 16 on my tablet, and everything seems to work fine except that I am incapable of encrypting. The first time that I attempted to encrypt the device, it seemed to be partially successful, but then I was trapped in TWRP with the "Keep System Read Only" prompt and my internal storage showing 0 MB. Nothing that I tried could escape constantly rebooting to this message, so I assumed that I was unable to mount internal storage, wiped+formatted it and planned to clean install LOS and pico Gapps.
At this point I noticed that my external SD was unable to be recognized either by the tablet or my PC via adapter for some reason. I pulled new copies into internal storage via USB and clean installed that way. I assume that my Nandroid and Titanium backups are lost and that the SD card will need to be reformatted.
Now on the fresh install, I attempted to encrypt again, but this time I just see the encrypting droid picture for a few seconds and then the system reboots. Any recommendations on other things to try? I unfortunately cannot restore any backups unless I figure out a way to extract data from my External SD, and I'm wondering if whatever happened to the SD card is related to the encrypting problem.
EDIT: With further screwing around, I was able to make encryption work, but things feel off. I occasionally see the "Keep System Read Only" prompt in recovery and the device seems sluggish and occasionally glitchy. So I plan to nuke the device from orbit and start over with a clean slate. The smart way to do that would be to format internal SD, flash stock firmware in download mode, flash TWRP in download mode, then install LOS and Gapps, and then finally encrypt the device, correct?