Some faces appear black or invisible on built packages and standalone view

Hi everyone, I’m doing my first UE project, coming from 3Ds Max and Vray via Datasmith.
I had pretty much fixed all the issues I could find with my lightmaps and shaders, and the visualization looked quite nice on my editor. I built a Win64 package (shipping mode) but I was surprised to see a lot of errors.
Here I share you some screenshots from the Editor, Play in Viewport, Play in New Editor Window, and what it looks like in the built package and in Play in Standalone Game
Does anyone know what could be the problem?

thanks a lot!

Ok, somethings going on.
I closed Unreal, and when I reopened it, I have this problem on my editor window also.
It’s not a problem with the shader because It’s the same used in other meshes that look fine. Lightmap density seems fine too.

TLDR -> Set Destination Lightmap Index to 3 on the objects with black faces.

Just started using Ue4 and this was the first problem I’ve encountered, opening the static mesh up I could see that theres an extra UV channel being generated.

UV 0 is a random channel that is being made when imported via data smith.
UV 1 is my diffuse channel made in 3ds Max
UV 2 is the Lightmap channel being made by Unreal.

What looks to be happening is for some reason some objects start using UV 1 as the lightmap channel. So just change the Static Mesh to use “Lightmap Index” 3 and rebake.