Changing scalar parameter values creates artifacts?

Hi.

I create a dynamic material instance. And change the Hue of a texture. The result are these strange artifacts.
I double and triple checked. No weird mesh issues. Even tested it on other simple box geometry.

Anyone experiencing this?

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Amazingly when posting the stats of the car on another thread i noticed it has an extremely high vert count.
Somehow when exporting this car it duplicated the mesh. So if though in my 3d app i did not have a double mesh, in UE4 i do.

Fixed.
Thank you

Oh i was mistaken. Seems all meshes reflect double the verts than in the 3d package. Strange.
So i guess its back to finding out why these artifacts happen