Could someone explain what is happening here (Packaged Project)

I have a large project. We have a fully static area with built lightmaps and HLODs. We are also using HSIMs. After loading the scene you see this:

or this

The lightmap is 4.6gb.

We are targeting a very specific setup so the results should be the same on every machine but this lightmap garbage happens at random.

This happens without quitting the executable. This happens when moving to a main menu level and loading the level with the pictures you see. The area is split up into sections. The section you are looking at is Section 1. Sometimes section 1 is fine and section 2 is garbage and vice versa.

It feels like it is struggling to load either the lightmap or the HLODs consistently but I need more information on what is going on in order to fix what the problem is.