Are you using a proxy or VPN to connect?

This issue can be caused by corrupted cookies or cookies that are blocked.

• check the permissions on the about:permissions page and in "Tools > Page Info > Permissions"
• https://support.mozilla.org/kb/fix-login-issues-on-websites-require-passwords

Clear the cache and remove cookies only from websites that cause problems.

"Clear the Cache":

• Firefox > Preferences > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox > Preferences > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

There is no Tools> Page Info > Permissions. I'm using Firefox on a Mac

There should be this page on Mac as well.

You can inspect and manage permissions for the domain in the currently selected tab via these steps:

• Click the "Site Identity Button" (globe/padlock) on the location/address bar
• Click "More Information" to open "Tools > Page Info" with the Security tab selected
• Go to the Permissions tab (Tools > Page Info > Permissions) to check the permissions for the domain in the currently selected tab

You can inspect and manage permissions for all domains on the about:permissions page.

• https://support.mozilla.org/kb/how-do-i-manage-website-permisions

You can open about: pages via the location/address bar.