Domain verified but stuck on "linked to another Vercel account", need manual detach

Domain: layeredconstruction.com and www.layeredconstruction.com

I own the domain and control DNS at my registrar. My _vercel TXT record (vc-domain-verify=…) is live in public DNS and ownership is verified at team level, but the domain is still held by an older Vercel project in another account I can't access, no previous developer can be reached.

My site is hosted through Marblism on their project. Marblism have confirmed in writing that the domain is held by an older Vercel project outside their platform and that they cannot release it. There are no projects in my own team scope to add it to.

Please detach both domains from the previous project so I can route them to my site. Happy to provide DNS screenshots and the hosting provider's written confirmation.

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.

https://vercel.com/docs/domains/troubleshooting

vercel.com

Troubleshooting domains

Learn about common reasons for domain misconfigurations and how to troubleshoot your domain on Vercel.

the troubleshooting guide has not been helpful.