What version of OS? KDE 5 or 6? X11 or Wayland? Do you have the same issue with Firefox in [https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Troubleshoot Mode]? Try downloading Firefox from Mozilla. Download, unzip, and 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 You can also create a new profile, switch to it and see if you have the same issue and then go back to your old one. about:profiles / see screenshot