Tex. Est. Code § 33.101

If probate proceedings involving the same estate are commenced in more than one county and the court making a determination of venue as provided by Section 33.053 determines that venue is proper in another county, the court clerk shall transmit the file for the proceeding in accordance with the procedures provided by Section 33.105 to the court in the county in which venue is proper. The court to which the file is transmitted shall conduct the proceeding in the same manner as if the proceeding had originally been commenced in that county.