Hey thank you so much for the response and going through the effort of re-creating the issue!
I figured out the black spots were caused by something to do with the static mesh. I hadn’t tried rendering the mesh in 3ds max (like a dummy) and saw that the issue arose before the mesh even made it to UE4. I recreated a similar landscape using the same technique and had no issues. Something went wrong at some point when making the mesh in max. Black spots are gone!
I am still having the issue with the strange lighting at the base of hills and dips. I am using the light map resolution of 8 but that didn’t seem to do the trick.
Here is the issue at night:
Here it is in the mesh editor:
Here it is in a 3ds max render (not quite as obvious):
If it matters I made the hills/mountains with soft selection and just moved them around. I checked all of the Z values at the base of the extruded terrain and they are all the same. Since all the Z values are the same, they shouldn’t be casting shadows on each other, right? The issue appears in 3ds max as you can see above. I can go ask the autodesk forums if it’s better suited there.
Is it maybe something with the material? Still using just base color and roughness at 1.