Connect a constant vector with a value of 0 to specular 
-> after that it should work (also make sure that you use the material setup that I posted)
- apply the material to all lod’s
- when it doesnt work, try to use a lower value at subsurface
Connect a constant vector with a value of 0 to specular -> after that it should work (also make sure that you use the material setup that I posted)