sorry for the delay, I haven’t forgotten about you. I just didn’t have a complete enough answer yet. It’s hard to be familiar with all of the projects that exist, and how they interact with MetaMask. So I wanted to look into them a bit further to make sure it wasnt an issue there.
It sounds like this may be related to trouble within the browser itself.
Have you updated Brave? Or tried creating a new user profile in Brave, then reinstalling MetaMask?
Might also be worth giving Firefox a try.
I know you just did this, and I hate having to suggest doing it all over again. (was kinda hoping there was an issue that wasn’t your browser. I know how annoying having to do the same thing repeatedly can be)
But if it is a issue of that specific browser instance, as I suspect, using a different browser would work around that problem and get you access to your accounts again. For the long term, getting the issue with that installation of Brave resolved, is the goal (Brave’s support will be far better at assisting on that than I will be.)
The Chainlist and CoinGecko methods are my personal preference:
chains - https://metamask.zendesk.com/hc/en-us/articles/360058992772