Have you tried Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#search I closed my account sometime ago, but the login still works. see screenshot

It is possible that Chase no longer supports your Firefox 78.15.0 version that is the last version for your OS (i.e. you can't update to a more recent version) and in that case you are out of luck.

It is possible that Chase no longer supports your Firefox 78.15.0 version that is the last version for your OS (i.e. you can't update to a more recent version) and in that case you are out of luck.

Supported browsers

   Chrome 95.0 and higher
   Firefox 98.0 and higher
   Safari 15.0 and higher
   Edge 95.0 and higher

We don't support:

   Beta or development browser versions
   3rd party browser extensions

Required operating systems

Windows® operating system:

   Windows 7 and higher

Macintosh® operating system:

   High Sierra (version 10.13 and higher)