Hello! I’ve had another issue recently with meshes, When I export them into studio it appears they aren’t the same mesh as in blender, I don’t know if it’s a glitch because I’ve never experienced this before.
I would guess it would be a problem with either duplicate-faces, in which selecting the whole mesh in Blender and hitting “Remove Doubles” would fix it, or the normals could be messed up, in which case selecting the whole mesh in Blender and hitting Ctrl-N should fix it.