I've tried this on Windows and macOS with Firefox, Chrome, and Edge.
When I go to the support site (https://help.guildwars2.com) and click the Sign In button at the top next to Submit A Ticket, it goes to a login page. Once I login, it redirects me to the https://account.arena.net/overview page. When you click "Support" at the top right, it goes back to the support page but you're not signed in. Click the Sign In button, shows the login page, then you're sent back to the account overview page. It's a never-ending loop of not being able to sign into the support site.
