do you mean it does not load at all? or what exactly happens?
Am experiencing the same issue on a fresh install of PVE 6.0
Uploading a Windows Server ISO (takes about 7 minutes) logs out before the upload is complete and fails with error 401 Invalid PVE Ticket.
I have the same problem, proxmox ver.6.0. I work 5min and the gui logg me of... :-(
Hopefully this is something of a Dr.-Emmett-L.-Brown-Effect ...
Now, as I'm back to future ( ), everything works as expected.