Stuck on "The identity verification was not successful. This is because the primary contact details did not match." What are they matching primary contact details against?

Question

"The identity verification was not successful. This is because the primary contact details did not match."

I am stuck here in verification, I am the account admin, can't edit the primary contact details (but it says only admin roles can), not getting responses in support, and don't know what it is trying to match primary contact details against.

Please help!