Interesting... Does it happen under a different user account? You can also try Refresh Firefox. https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

You can do a malware scan, just to be sure. *https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware You can check the connection settings. *Settings -> General -> Network: Connection -> Settings If you do not need to use a proxy to connect to internet, select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly. See "Firefox connection settings": *https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors This could be a problem with the TLS 1.3 Early Data feature also known as Zero Round Trip Time Resumption (0rtt). You can try to set <b>security.tls.enable_0rtt_data => false</b> on the <b>about:config</b> page to disable this feature. See also: *[/questions/1376015] Issue with most Google sites on Firefox v100 64bit