An extension might be causing your issue: I'd check those first. You can try the following:
• Menu -> Extensions and Themes -> click the ⚙ -> Check for updates
• Menu -> Help and Report -> Troubleshoot Mode
If sites work fine in Troubleshoot Mode, that would point to an extension.
You could also backup your data, and create a new profile, then bring it back:
• Menu -> Settings -> Account and Sync. -> Backup -> Turn on backup (unless you use it already)
• Then tap ALT to show the old menubar, and on the Profiles menu, choose "New profile" and set one up
• Once in the new profile, Menu -> Settings -> Account and Sync -> Restore to get your data back
Beyond that though, if you're still getting endless glitches and crashes in Firefox, you can install Google
Chrome, Microsoft Edge, Opera or Vivaldi on your PC. Any of them should ask if you want to import your
stuff from Firefox when you first open them. (And if you use a Mac, then Safari is also an option.)
Google Chrome: https://chromeenterprise.google/download/
Microsoft Edge: https://explore.microsoft.com/en-us/edge/business/download?form=MA13FJ
(should already be preinstalled though, if your PC has Windows 11 or 10 on it)
Opera: https://www.opera.com/download
Vivaldi: https://vivaldi.com/download/
