That is not a problem. Many home owners do not own mineral rights to their property as it could have been reserved by a previous owner, the HOA, or even the builder/developer.
In most cases when a Seller is retaining their mineral rights, they do not even know if they have any! They are just stating that they are retaining their interest to the mineral rights (if they have any to retain).
To know who owns what, an oil and gas attorney would need to review the chain of title and formulate an informed opinion.
