I am currently looking into this as I have done the sun already moving across the sky the new thing to notice is that the skysphere is actually a blueprint and not just a sphere.
I am writing a tutorial and video which you can follow I want to make it complete with possibly using their skyblueprint example.
So the current point now is to either adjust the blue print or put a static mesh in place of it with a sky material you will find that if you delete the BP_Sky_sphere from the level you should see your light moving.