Baked lights on instanced static meshes are buggy

Here is my project in UE4.26. I am trying to make these plank pillars look natural but the shading is all off whenever I build the lighting, the planks are instanced and are static inside of a blueprint. The lightmap resolution is green and the UV’s are correct. Any help? Also as a side note, whenever i restart the level the lighting ‘unbuilds’ itself.
Plank with built lighting:

Plank with unbuilt lighting: