I've recently upgraded to Big Sur OS. Not a good experience: all my data disappeared. It took weeks with Apple techs to get things to work. But once restored, Firefox had number of issues. Pages reloaded after restart that I'd closed days ago. Many extensions no longer work. When I finally sat with a local Apple tech, his explanation was that the switch by Apple from 35 bit to 64 meant there's an incompatibility. (or 64 to 35??) So I've had to move to Safari. There are many many features I miss in Safari. Is there some other solution that would make FF work for me? I guess I could try again, and test the extensions one by one to see if I can find what's causing the problem? thanks very much.