I've been seeing "Exception: QuotaExceededError: The quota has been exceeded" a couple times a day recently. This is on Firefox on Mac OSX currently but will attempt to test on Chromium Edge next.
Found a hit on the internet for Chrome and FF and that link talks about cache issues but no real details.
I think I found a config screen that might help troubleshoot though:
Preferences » Privacy & Security » Manage Site Data — has a screen that shows storage amount.
Will keep an eye on this to see if there's a correlation to the error popping up.