Lighting/Shadow issue (UV Overlap by 94%!)

Hey guys! First time posting here, I have a bit of an issue that I can’t figure out. I apologize if this has already been answered, but I can’t seem to find the right thread.

I’m making my first environment in UE4, using purely stock and marketplace assets, nothing I’ve made myself (so far). For the most part everything is working out great, but whenever I build my lighting, I have a few foliage assets in my level return the following error (roughly):

Error: UV lightmaps are overlapping by 94% (yes, that number is accurate, lol).

This affects a few of the assets I’ve used in the environment, most were placed using the Foliage tool, but the biggest problem is with a large tree in a field. After the lighting is built, the shadows appear fractured/grid-like on the tree itself: (may need to zoom to see the tree). The asset pack is called Foliage Tree Pack.

I’ve been searching for a fix, but everything I find seems to address assets that people are making themselves, and therefore I can’t seem to actually find or change any of the settings being suggested. Either I just can’t find them, or they just automatically revert back to the “default” setting. Any ideas on what I’m doing wrong? I’m super new to this engine so I must be missing something for the overlap # to be that high.