Odd; now that I'm logged in there, I can head straight to support.pso2.com with no issue.
Maybe it's a browser problem? I'm using Firefox 84.0.2 (64-bit), but I'll go ahead and do a quick check in a couple of others.
EDIT: It's the exact same for Chrome, Edge, and Vivaldi on my end; as soon as I am logged in, I can just manually go straight to the support site, though the auto-redirect that used to happen is no longer happening.
Still happening for me. Using Firefox 84.0.2 (64-bit) on Windows 10.