Okay so I have a solution to your issue:

I recently rooted my V20, and all was going well, for about... 3 weeks? Cool. Phone is faster, everything looks better - more customization, etc etc.

THEN LineageOS decided to FUCK me. Real good. Like ENORMOUS black dildo in my ass.

I decided to restart my phone tonight and I thought everything would be cool, right? I've restarted my phone on multiple occasions now. WELL. Hohoh. Everything was NOT OK.

I couldn't turn my phone on at all, right? OK. Took my battery out, restarted phone - couldn't use my fingerprint scanner. Hmm. Weird.

Unlocked phone the conventional method - NovaLauncher setup screen for some reason... Weird. I already have it set up, why is it asking me again?

Well. Turns out I kept ALL of my apps on my phone, but any data associated with them was wiped? The HELL?

Anyway, long story short, don't root your V20. It's been a nightmare. Unless you enjoy being anally raped by giant black dildos and then being forced to eat shit and die. IF you like those things, please follow this simple guide and you'll have what you want. You're welcome. Best of luck. Prepare your anus.