I updated now as well to FPOOS 17.01, on an encrypted devices, and also encountered problems (maybe also @anon36364121 might be interested) .
I was following the update guide.
After the initial update process is finished in TWRP, and when the phone reboots, I usually go to recovery again right away to reinstall opengapps & xposed. However, I could not access recovery! When pressing [power] + [Vol up] the phone just rebooted twice after a short time (not sure if I can talk about a loop, as I aborted after not being able to enter recovery).
What I did to solve the problem was to install the community port of TWRP (as I still could get into fastboot). After this I could enter as usual into recovery and installed opengapps, xposed & Fdroid.
After that the phone rebooted normally, and I am running 17.01 now.
I tried to flash again the TWRP shipped with 17.01 manual-userdebug file and then could access the recovery as usual. I don’t know why it did not work after the update (which I initiated through the FP updater). It could be that either the recovery from the ota-update file was faulty or did not get installed properly. Though I didn’t experiment too much with it, I just tried to get my phone working again asap.
Anyhow, now running 17.01. Thanks for finally fixing the video focus 