Fingerprint error fix:
Twrp doesnt restore the persist partition correctly!
rename the persist.emmc.win from the twrp backup to persist.img and flash it in bootloader via "fastboot flash persist persist.img"
Worked a charm! Hofa to the rescue, not just one, but twice! Thanks a tonne! You honestly have no idea how much stress that's relieves :3
So because I've had dm's of people running into the same issue, I'll update the main post with my solutions:
Steps I took for this fix
1) Went to my nandroid/TWRP backup (which was taken ~2 weeks ago, back on the A11 OS update patch)
2) Located file "persist_image.emmc.win"
3) Renamed it to persist.img
4) On PC, opened powershell window (shift right click on windows) in the same file as the persist.img file
5) Sent adb command "adb devices" to check if device responds, if listed, sent command "adb reboot bootloader" to get devices into fastboot mode
6) Sent command fastboot devices to see if device responds, if listed, sent command "fastboot flash persist persist.img"
7) Took 1.5 seconds to sent 54000 ish KB. Shoud see OKAY's on powershell screen
8) sent command "fastboot reboot" to boot phone up.
Should work from there!