Shadows broken on landscape only?

After building light with different resolutions on the landscape, I still have an issue where the shadows are “blobby”.
As you can see in the image, shadows work on everything except the landscape. Any solution would be very helpful. Thank you.

If the landscape is too big, you would get that result.

I set up the same assets in a smaller level and still got the same results. Originally, I tried to double the landscape lightmap resolution by setting it to 2. After experimenting, I set it to 10, and got the results I was after. It does not seem to have affected my frame rate.