I've been having this same problem for almost a week now. I am using a VPN (NordVPN), but this has never been an issue before. For some reason, I can access my characters just fine on my phone (using the same VPN), but it doesn't let me on both my PC and my laptop. I also can't access any of my players' characters. None of these characters have any Homebrew, so that can't be the problem.
Hello! Please see this article from NordVPN.
Yeah it's started working for me all of a sudden, not sure what I changed I'm afraid.