Uneven lighting on spline meshes and adjacent static meshes

I’ll get back to you on that. I think I also found a workaround, but I’d also like to see what would happen if I copied the project to our team’s 4.8 environment.

The workaround was this:
Under Transform, I had meshes mobility set to Movable
Under Lighting, I went to Show Advanced and changed Indirect Lighting Cache Quality to ILCQ Volume.