Cannot adding dpdns.org domains that is in Public Suffix List

I’m having trouble adding the domain “*.dpdns.org” to my Vercel project.

Although I’ve confirmed that this domain is not being used by anyone else, the system still indicates that it is occupied by another account. I tried adding records and changes name servers, but the issue persists.

This domain is provided by DigitalPlat as a secondary domain service, so I can only manage the DNS records for secondary domains, like “_vercel.*.dpdns.org”, and cannot directly change the records for the top-level domain.

To illustrate this issue, domains like ".eu.org" and ".us.kg"are considered top-level domains and can be verified subdomains without problems.

But new dpdns.org domains are not allowed. Even they already in Public Suffix List.

The domain troubleshooting guide can help with most custom domain configuration issues. You might be able to use that guide to solve it before a human is available to help you. Then you can come back here and share the answer for bonus points.

You can also use v0 to narrow down the possibilities.

Closing this topic as we’ve continued the conversation in another thread