iCloud Mail - Logs out iCloud

Been having an issue with iCloud. I sign in to iCloud at work using Brave browser. When I go to check email I would get logged out of iCloud when selecting an email or deleting email if it didn't log out when selected. I tried several different browsers, Edge and Chrome. The laptop I use at work is Windows. So I figured I will see if I happens on my Mac at home using Safari. Same result when going into email and selecting an email iCloud would logout.

Has anyone else experienced this issue and if so where you able to correct it?

Thanks in advance.