Just in the last few months I have had an issue logging in to the Web UI with certain browsers. Right now Microsoft Edge seems to be the only one that works. The behavior is that I get the Proxmox VE login box with the ability to enter all the information. Even though it is entered correctly when I click the Login button it never gets past this step to get to the portal. The Login Box just remains there. Chrome and Brave no longer work and I have to use Microsoft Edge. I have not tested with other browsers at this point.