Tessellation causing double layered seperation?

After upgrading my project from 4.25 to 4.26, all the meshes in the level that had tessellation have separated into 2 layers, the tessellated portion and the the original flat fake mesh. I have tried redoing the meshesb UV and normals in maya to make sure everything is ok, and reexporting to unreal but to no avail. Please help and thank you for your time :slight_smile: alt text