@Ignorant@Thumperchick Nope, not logged in there (all the sites have individual login sessions). It’s really weird. I tried a private browsing window, and the login page loaded fine. But in a normal window, I get a 404 (with the Cary Grant gif). Now I know the issue is on my end, so thanks for the help everyone.
@RiotDemon It’s fine, I can use private browsing to get around the issue for now. There’s probably some kind of (temporary) issue/mismatch with my setup/security and that site specifically. All of the other mediocre sites work with no issues.