Steps and link to replicate? Do we have to login to replicate the issue? Did you try 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 try clearing the browser cache? https://support.mozilla.org/en-US/kb/how-clear-firefox-cache# Windows home or pro and what security software are you running besides MS Defender? If pro, you should have '''Windows Sandbox''' enabled for testing. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/