Wireframe issue after Export from 3d max

Hello. After a few exports, I noticed that on the wireframe map I see this (on the right part of the picture). something is not right. There are two UVs channels. first for textures and second (clean) for lightmass and no collision. I am not good at 3d max and UE4 also. If someone knows why this is happening, pls, answer this would help me a lot. It’s hard to navigate and drag meshes around when this mess disturb