No information about NotServedByPagesError in GitHub pages documentation

[TokugawaTakeshi]

Creating the GitHub page, I has been told:

Both yamatodaiwa.com and its alternate name are improperly configured
Domain does not resolve to the GitHub Pages server. For more information, see documentation (NotServedByPagesError).

If try to search NotServedByPagesError in GitHub Pages official documentation, no search results will be:

The interesting thing is despite the error page is displaying on specified domain!

Additional information

About GitHub pages limitations

The CNAME file must contain the domain name only. For example, www.example.com, blog.example.com, or example.com.

To be honest, I has not understood this limitation correctly.
I have apex domain yamatodaiwa.com and also es-extensions.yamatodaiwa.com, but I want to associate with each of them separate GitHub repositories. As I got experimentally, it is possible.

DNS records

The current DNS records are:

The A recordings has been set according the instructions for apex domain. The CNAME records has been set according Configuring a subdomain instuctions.

Screenshot

[yoannchaudet]

DNS propagation is not immediate. GitHub will not be able to tell you if your DNS configuration is good until it resolves from our side of the Internet.

If you are curious about the code that leaks in the error message, it comes from https://github.com/github/pages-health-check/blob/e1d29db4510709f7bd8095a4b534575cb90b0f14/lib/github-pages-health-check/errors/not_served_by_pages_error.rb#L6.

Checking your site now, I can tell your certificate has been obtained so I assume DNS eventually propagated.

[alexellis]

I have run into this today, with a newly created record. DNS on my network propagates very quickly, but I often find that GitHub (including when dealing with webhook URLS/domains) can take hours and hours to update.

[TokugawaTakeshi]

I have faced with this problem again once changed the domain. A few days have passed, so this time the cause is definitely not the delays of DNS propagation. Where I can get the help now?

I have created the single image with configuration of 2 sites (apex domain + subdomain) in GitHub, domain names provider and GitHub documentation. Currently both domains not directed to GitHub pages.

[yoannchaudet]

@TokugawaTakeshi This is what I get when I resolve your domain:

That's not Pages.

Your domain is still managed there:

[TokugawaTakeshi]

@yoannchaudet
Thank you for the investigations.

Does it mean that something wrong on the side of my domain provider?
If so, I'll contact with the provider, but if I say just; "My domain don't resolved on GitHub page" I'll be answered: "I don't have not hear about GitHub page. Please contact to GitHub customer support". What I need to show them to prove that the problem is on their side?

[yoannchaudet]

From my part of the world, I see the following when accessing your domain:

So yeah I believe you have a configuration issue somewhere or a domain transfer that is slow to happen.