"Can you tell me what you’re “Light Map Coordinate Index” is set to in the static mesh editor for these models?"
Walls: 1
Floor: 0
Ceeling: 1
If “Light Map Coordinate Index” is set to anything other than 0, then use the drop down list at the top that says “UV Channel 0” to select the UV channel “Light Map Coordinate Index” is set to and retake those screenshots of the UVs.
Walls
Ceeling
One last thing. I was speaking from memory before and now that I’m looking at unreal I see that I missspoke earlier. Instead of increasing “Min Light Map Resolution” which is for light map auto generation, increase the “Light Map Resolution” setting in the same “Static Mesh Settings” section of the Static Mesh editor I mentioned above.
I did set them to 512. The min resolution is 64