You can try
Settings → Shields → Trackers & ads blocking: Disabled
Then, you need to disable the Shields on youtube.com and google.com on first visits. Once that’s done, you can reenable it. Then use uBlock Origin or your preferred adblocker in its place.
Note that this could possibly be happening on ANY page embedded with youtube.
Barring that:
I recommend backing up what you can on the browser. Then make a back-up of
C:\Users\ [user]\AppData\Local\BraveSoftware\Brave-Browser\User Data
Once that’s done, update your browser. Unfortunately there isn’t much else that can be done at the moment.
Keep an eye on these threads for possible news updates: