My voxel models look very weird

So, I made a map with magicaVoxel. After exporting the models onto 3Ds Max and creating a 2 UV channel for the light map(Otherwise prop will turn black) I get this very bad quality model. Does someone know how to fix this? thanks in advance!

Can you elaborate? From my understanding, voxel models are really low quality models in the first place. Is it supposed to have all of those pieces missing, or is it supposed to be like a solid wall? Are you referring to your lighting or the actual mesh? You only need 1 UV for materials and 1 UV for the lightmap.

is your problem related to the voxel models or the lightning?