Have you tried with Firefox in Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Did you clear your browser cache? https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox You can also try Refreshing Firefox. https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings Try downloading Firefox from Mozilla, run '''firefox-bin''' from the folder and see if you have the same issue. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release What desktop? X11 or Wayland?

Thanks for the reply. Literally an hour after I posted this I checked if there were any updates for Fedora 40. Turns out there were many system updates. I applied them all, rebooted and Firefox was back to normal. So, I'll consider this closed for now.

Great. Mark it as resolved to get it off our plate and have a good day.