Hi ftavares, sorry to hear about this problem.

Your Firefox may have logged some data that would help track down the cause of the problem. You can submit that data to Mozilla and share it with forum volunteers to see whether it points to the solution. Please check the support article "Firefox crashes - asking for support" for steps to get those crash report IDs from the about:crashes page -- or, if necessary, from files on disk -- and then post some of the recent ones here.

ftavares said

I have Bitdefender installed, testing to see if this makes it go away by uninstalling it.

Sounds like a good thing to test. In another thread, a user reported this problem could be caused by Bitdefender:

https://support.mozilla.org/questions/1280327

I haven't looked at Bitdefender's support pages to see whether this is a known issue with a workaround.

Note that a bug report has been filed to investigate this issue.

• Bug 1616993 - Reports of tab crashes caused by Bitdefender

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)