Mineral rights inheritance in differing states

I am the executrix and sole heir of the estate of an individual who died and whose will was probated in Texas. Several months after filing the final inventory, I discovered paperwork relating to royalty payments and a mineral deed located in Oklahoma. Therefore, these assets were not entered into the Final Inventory that was accepted by the courts. To save money (since the royalties were not large), the oil and gas company agreed to write checks to the estate. These royalties dried up and the well was capped. Two years ago a different company approached me seeking to lease my minerals and I agreed. I have a lease agreement that is in my name (as the sole heir of the Estate). Now I have been mailed Division Orders from an Oil and Gas Operating company that is refusing to release my royalties until an Ancillary Probate for the mineral deed is processed in Oklahoma. My question is, is there some way around the Ancillary Probate. The deceased has no living relatives, never married and had no children. (Her two sisters pre-deceased her and also never had children.) I do not have the resources to spend on an attorney and have very limited income. It just seems to me that since I’m the sole heir, as stated in the will, I should not have to do anything else. (I believe the will was filed in the county where the minerals are located by the Oil Company that entered into the lease agreement with me.) Couldn’t the royalties continue to be paid to the Estate if the company is concerned about heirship? Please help!!