Generating Global Illumination not working in large scene?

I have two scenes. The first scene is a small plane about 50 meters with some models marked as static. The second scene is a 2,000x2,000 meter terrain with the same models marked as static. I have the exact same global illumination and light map settings, same light, and same camera. The only thing that is different is the scale of the scene thanks to the terrain.

The global illumination in the large scene calculates but doesn’t appear to work but when in the small scene it does. Why? Is there a setting I’m missing here? Does it just not work for large scenes?

Thanks in advance!

It should work for both scenes. Did you set the objects in the large scene to lightmap static?