I set up a new domain and www subdomain to point to the gitlab pages for my group, by following the instructions For both root and subdomains. When I access the page through the root domain, it works. However, when I access it through www subdomain, I get a 401 access error. Different from some other questions on this topic, both root and subdomains are verified.
So the CNAME is working correctly, but gitlab seems to be refusing access based on the specified host in the HTTP header, despite the www subdomain having been verified and added as a domain to the Pages configuration.
Not sure what else to try and fix it. It’s particularly annoying because it seems that when I type the root domain in Firefox, Firefox automatically and unhelpfully adds “www.” to the front, making my page appear to not work at all.
One thing I’ll note, is that I left the automatic Let’s Encrypt turned on, and it is currently waiting for a certificate for more than a day, so I am not sure if that contributes to the problem and will fix itself when the certificate is available, but it seems the root domain access works fine so I don’t think that’s at play.
Edit: I should mention, project visibility is set to Public, and Pages is set to Everyone With Access.