Non-Displacement Lighting Issues

[Atasco]

Dangit, fellas

It's no longer even a displacement, it seems like any object that occupies that space gets a lighting glitch of it's very own. The only thing in the map right now is a skybox light so I don't understand why it's doing this??? There's literally nothing but solid brushes. Everything is using the same lightmap scale, is selected to be treated as one, and I even put it in a smoothing group and nothing is working.

EDIT: It works now???? I selected all the offending faces and pressed the B button that has no tooltip so I have no idea what it does, and it suddenly works like a dream. Everything is shaded just fine. I'm so mad.