Movable sun interfering with landscape and skydome

So, i have made a new map with a landscape and the default skydome. In this level i have made a movable sun BP so my sun can move and have dynamic lighting(i also set the directional light to movable). The problem is that when the sun goes under the landscape the sky doesn’t become dark, but stays in sunset mode. (note: the material has multiple textures and has a grasstype)Also, i can see light from the landscape coming out when the sun is under it. Is there a way to fix this?