Across a full browser restart, and with ad blocker disabled, I can access the main unrealengine.com site only while not authenticated. As soon as I authenticate, there is an endless redirection loop. This persists across a full restart of browser and re-authenticating.
As you can see from this post, forum logins are working fine.
UPDATE: The original report was from Firefox 154.0.1. I have reproduced the issue with a brand-new installation of Chromium 153.0.8010.52.