the rotator node is expensive. if you want a 90 degree rotation and you insist on doing it in the material then just swap the x and y components of the UVs around.
Hi! It's because the UV orientation is different between the preview sphere and the mesh. Easiest solution, assuming this is a directional pattern, would be to change the orientation of the meshes UVs (rotate by 90 or -90 degrees), so their orientation is consistent with ones of the preview sphere. To solve it in the…