I've had this for a while now, sometimes it logs in fine but a lot of the time it just doesn't.
Making a new unity account and logging in with that works, but I shouldn't have to do that. Especially since I'll probably be buying a license soon, and I'd want that to work.
I've tried uninstall/reinstall, downgrading versions, signing in or out with other linked unity accounts, doesn't seem to help.