My site’s core login feature has stopped working. The problem isn’t design or speed—it’s pure functionality. Every time a user tries to sign in, the request fails because of what appears to be a domain-related issue. Here’s what I need from you: • Diagnose the exact source of the login failure, including any mis-routed domain or DNS settings that could be blocking authentication. • Repair the issue so registered users can log in without errors and new users can register successfully. • Confirm that password resets and session handling still work once the fix is applied. • Provide a brief report of the steps taken, so I can keep track of the change history. The job is complete when I can sign in from multiple devices, the login form returns no errors, and there are no unexpected redirects tied to the domain. If you’ve tackled similar authentication problems before, I’d like to get this sorted quickly.