[help] Static light on a movable mesh gives wrong shadow (using Volumetric Lightmap)

Hey guys.
So, this is the last problem for my project where I can’t have nice (or even right) shadows on my movable door using only a stationary skylight (no directional light either). The parts that are in direct contact with the light source (window) are kinda acceptable, but behind it gets so messy, with shadows too far from my mesh (the door is touching the ground) and shadows passing through the mesh (pic 3). I’m really out of the ideas here. Can someone light my way here?

Images: Volumetric Lightmap problem (UE4) - Album on Imgur