Using current Firefox (84.0.2) on an iMac desk computer. Since Apple put out their recent upgrade to OS Big Sur (2019 ~Nov?), Firefox keeps dropping its internet connection. Works for a session, but when I come back a few hours later I see "Unable to connect..." Restarting always gets it back to start another session. But rebooting several times every day gets old. When Firefox is on the blink, Safari browser works fine, no problem. Connection is there. But my fullest set of bookmarks is in Firefox, so I'd rather use Firefox. Even more strange: Safari and Firefox both continue to work on my wife's desktop same iMac, no problem, just not Firefox on mine. Found help article "Firefox can't load websites but other browsers can" (https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can), went through every step to troubleshoot. No go, still drops. Contacted Apple support and they were flummoxed. Any ideas?