Your DNS looks correct now. I checked it from outside (Google and Cloudflare resolvers, plus the .ru registry):

• tebicamp.ru A → 185.199.108.153, .109.153, .110.153, .111.153
• www.tebicamp.ru CNAME → alexastrela.github.io
• No AAAA, CAA or DS records, so nothing blocks the certificate
• The .ru registry (RIPN) already delegates to leonard/thea.ns.cloudflare.com, and your repo's CNAME file contains tebicamp.ru

So the InvalidDNSError is most likely a stale result from before the move to Cloudflare. The DNS check does not always re-run on its own after a nameserver change. To force a fresh check:

1. Go to Settings > Pages, clear the custom domain, and save.
2. Wait a minute, enter tebicamp.ru again, and save. The DNS check runs again.
3. Once it passes, certificate provisioning can take up to an hour. Then tick Enforce HTTPS.

Keep both records on DNS only (grey cloud) in Cloudflare, as you have now. If the check still fails after re-adding the domain, run dig tebicamp.ru +noall +answer and post the output here.

Hello GitHub Support,

I'm trying to configure my registered domain mahdi.bd for GitHub Pages under the GitHub account YaminMahdi.

Repository: https://github.com/YaminMahdi/yaminmahdi.github.io

GitHub rejects the domain in both locations:

• Repository Settings → Pages: InvalidDomainError, “Domain is not a valid domain.”

• Account Settings → Pages → Add a verified domain: “Domain is not a valid public domain.”

My DNS is configured through Cloudflare. The apex domain has all four GitHub Pages IPv4 addresses, and www.mahdi.bd points to yaminmahdi.github.io.

I've verified the DNS configuration using my local resolver, Cloudflare DNS (1.1.1.1), and Google Public DNS (8.8.8.8). The public resolvers return the expected GitHub Pages IP addresses and Cloudflare nameservers.

Additional observations:

• Visiting http://mahdi.bd successfully loads my GitHub Pages website, despite the domain validation failure. However, HTTPS is not working, and the site is accessible only over HTTP.
• I came across a report from another user suggesting that second-level .bd domains, such as example.bd, are rejected in Account Settings → Pages → Add a verified domain, while third-level .bd domains, such as example.com.bd, are accepted. This makes me suspect that GitHub's domain validation may not correctly support second-level .bd domains.

DNS diagnostic commands:

dig mahdi.bd A +short
dig mahdi.bd AAAA +short
dig www.mahdi.bd CNAME +short
dig @1.1.1.1 mahdi.bd A +short
dig @8.8.8.8 mahdi.bd A +short
dig @1.1.1.1 mahdi.bd NS +short
dig @1.1.1.1 mahdi.bd AAAA +short

Observed results:

185.199.109.153
185.199.110.153
185.199.108.153
185.199.111.153

yaminmahdi.github.io.

185.199.110.153
185.199.111.153
185.199.109.153
185.199.108.153

185.199.110.153
185.199.108.153
185.199.109.153
185.199.111.153

isabel.ns.cloudflare.com.
zahir.ns.cloudflare.com.

The results show that the apex domain resolves to all four GitHub Pages IPv4 addresses, the www subdomain resolves to yaminmahdi.github.io, and the nameservers are Cloudflare.

Since the website loads over HTTP and DNS resolution appears correct, could you please investigate whether second-level .bd domains are supported by GitHub Pages domain validation? If this is a limitation or a validation bug, please advise how I can configure mahdi.bd successfully and enable HTTPS.

Thank you.