Sometimes a lot assets like this do require some setup and fixing when bought from other CG sources. There are some that are “Game-Ready”, but often these still don’t account for a lightmap UV that is good for UE4 or have a good texture UV that works well with our in-editor lightmap generation. There are some good free tools out there for UVs or even Blender with following a tutorial you can get by just doing a flat mapping technique in most cases to get something that looks good enough to be less problematic.