I’m sorry you lost hundreds of tabs. That is so frustrating. Unfortunately, Browser Guard incorrectly blocked some legitimate sites because we had a database update that caused a false positive.

An automatic fix was deployed shortly after the false positive was flagged. We've also put in additional guardrails to prevent false positives like this from occuring again in the future.
This was actually fixed over 10 days ago, so it's a bit odd that you saw it 2 days ago.
If possible can you reach out to Support via our chatbot (it will direct to a live person) -- help.malwarebytes.com?