I have been using Firefox on my Mac to log into my bank for years. Over the last few weeks I have been getting an error message saying I need to use another browser. Until today, I was able to re-try and gain access. Starting today I could not log in at all using Firefox. I was able to log in using Safari. I called my bank's support line and and they say it's a Firefox issue. They talked me through clearing my cookies and cache. They even talked me through refreshing Firefox. None of that worked. On my own, I uninstalled and reinstalled Firefox, but to no avail.

I am able to log into the bank using Firefox on my PC laptop. Does anyone have any suggestions about why the Mac version of Firefox stopped talking to my bank and advice on how to solve the problem?