Unable to verify custom domain tadux.com - locked in unmanaged tenant I cannot access

mydomain - is a dummy name

What I've tried:

1. Internal admin takeover via Microsoft 365 signup - Failed with "UnknownSku" error
2. Attempting to reset password for existing ******@mydomain.com account - No access
3. Verified subdomain auth.mydomain.com successfully (proves I own the domain)

Business Impact:

I need to use mydomain.com with Databricks, which requires the apex domain for authentication federation. Subdomains won't work.

Proof of Ownership:

• I control DNS at GoDaddy
• Current TXT records: MS=ms57917542
• Successfully verified subdomain: auth.mydomain.com with MS=ms13856346
• Can add any additional verification records required

Request:

Please help me remove mydomain.com from the unmanaged tenant acb420d8-50ea-4478-adb2-2a592f94feb0 so I can verify it in my primary tenant, or provide guidance on how to take over that unmanaged tenant.