Shadows looking splotchy on terrain

Well… I’ve been working on a map for my game. The problem is that every time I build my lighting I get these weird splotchy shadows. When I go and un-click cast shadows and re-click it it becomes gorgeous again. Please give me an idea how to get the prebuilt shadows to show after their final lighting build!

These are the good shadows before I attempt to build them.

And after :'((((

Let me know what you think!

Check out this awesome lighting guide I found to solve this problem:

There is a specific section on splotchy shadows near the bottom. For me, I had bad lightmaps, so “force no precomputed lighting” in the world settings as described in the beginning of the article worked for me. Really, you should read the whole guide as I think great lighting is a holistic approach.