Shadows getting messed up when I rebuild lighting

So I’m fairly new to 3D stuff and I’ve been trying to learn at a slow-ish pace, and so far have run into very few problems that I could not solve myself. This on the other hand I have no idea how to fix nor can I find any documentation on it so I’m guessing it is either a unique bug or a very simple one that I am probably overlooking something. Basically what happens is when I load in a certain fbx object from Blender into my unreal the lighting initially loads in properly or proper enough like so .

The problem I’m having is that when I rebuild my lighting it tears the shadows and just looks awful afterwards like so: .

I have tried checking my UVs to see if I have any overlapping and from what I can see there is no overlapping. I have also tried going into the mesh editor on unreal and messing with a few settings there such as, enabling recompute normals and increasing the minimal light-map resolution. If anyone can help me solve this, or let me know other things that I could check to help me find the problem it would be greatly appreciated.

It’s probably a combination of bad lightmap UV’s and needing to increase the lightmap resolution