Users with Bitdefender security software installed may experience problems loading websites, particularly Facebook.com. We are working on a workaround, but as a temporary mitigation, disabling Bitdefender or turning off its traffic filtering features may resolve the issue.

Note that this HTTP3 issue is being investigated by Mozilla.

• 2034178 - Facebook does not open in Firefox 150.0 (HTTP/3 stalled by endpoint protection?)

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