@EndOfMyRope Officially/technically, there’s nothing that typically can be done. I mean, you could have exported/imported all your settings through Brave first, which would then have put everything back once you imported. Or you would have Sync option where you’d input the code and it would have applied your passwords, extensions, and whatever else you had decided to sync.
I’m guessing you went with copying your \brave-browser folder which would have successfully carried over everything except passwords, but encryption usually changes and you experience what you are.
In the past, people have tried things like using Chromepass which was able to decode, but lately there have been people who said that’s unsuccessful. If you want instructions on that to try though, I’ll say you can check out:
That said, I’ll tag @JimB1 and @CerealLover to see if they might have any other ideas
NOTE
Btw, if you ever synced with another device, you could sync your PC back to it. Have you not synced a phone or anything with it? Just mentioning in case that might be a very simple solution that just escaped your mind for a moment.