How do I have a 3d model have two unique textures while still being able to rotate the model?

This is such an absurd one, but for some reason as soon as a mesh face has a separate texture from the base models texture, it does not rotate with the meshes bones?

I don't really know how to describe it more than that, I've gone through so much bullcrap trying to figure out Why it is doing so? But i just cannot figure it out after hours.

(Gif links, one has both cubes rotating, the other has the cubes rotating except for one face)

postimg.cc/vgp1FjJK

postimg.cc/WFQDLKB5

Any help would be lovely! I need the faces to have separate textures so i can change them dynamically, while still keeping rotation dynamic as well!