Access Denied when creating Child Domain

I am attempting to use dcpromo to create a child domain on a new machine in my root domain.

Dcpromo fails with the message ‘Access Denied’ and ‘don’t have sufficient rights’. However, I’ve used the ifmember tool and it shows that I am Enterprise admin.

I can’t find other permissions that are off. I can re-add the machine to the domain just fine (dcpromo works enough to take the new server out of the root domain).

Is there a policy that I am missing? What could be denying me access?

(I’ve checked DNS through and through as well. The new machine has DNS for the new domain as standard primary, secondary for the old domain. It accepts forwards from the other DCs and they accept from it)