Why is light not building consistently across meshes?

I’m having an issue with light casing in very inconsistent ways across the meshes which make up my level’s rooms.
It seems like it’s building as I would expect on the closes room mesh, then it stops at the edges and gets vastly dimmer on any adjacent mesh.
I’m using auto-generated lightmap UVs since the meshes are pretty simple.
The ceiling is a single BSP I capped the level with since the meshes themselves don’t have ceilings right now.

Corner piece (seen to the left of the lightsource) and lightmap UV

Example light build

I’ve been doing some more research, and I suspect the problem might be inconsistent texel density. I’m going to make another pass at the UV maps and see if that will fix the problem.

Good day. Your issue is covered in this forum thread.

Thank you so much! I’m still working on applying some of the corrections from that thread, but I’ve already seen a big improvement.