Mesh not receiving direct light

I have three skylights in my hallway that allow the directional sun to light the floor immediately below it. But for some reason the light doesn’t appear on one of the meshes/materials.

The floor mesh extends to other rooms and in those areas they light up fine. The material is also used elsewhere where there are skylights and that works fine too. For some reason there’s a dark spot in this area only and I can’t figure out why…

Unbuilt/preview view definitely shows that it should be lighting up as well:

Can anyone help?

Make sure your lightmap UV’s are setup properly, and that your lightmap resolution isn’t too low.