Did you try with Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf

My only issue with Xfinity is that they are the only choice where I live.  ;-/ see screenshot

Thanks. But didn't help. Message I received: Secure connection failed and Firefox did not connect

Post a full browser screenshot showing the issue and not just the error message. What security software are you running? Are you running a Pro version of Windows? If so, try this option or any VM app to test the issue. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

It looks like they moved some pages around and old links are failing.

Could you try starting from https://www.xfinity.com/hub/

Toward the upper right, there's an account button (looks like a little head and shoulders in a circle) that opens a panel to sign in.

Any luck using the "Check Email" link on that account panel?

Thank you very much. I had found that funny account button Monday but my email would not work at that time. Last night I was able to log in. Just now though it said they were updating. But a few minutes later my email opened. I have no idea what they are doing but whatever it is it's a pain. Maybe they don't know either. LOL Thanks so much for your help.

Pam C.