Andrey Novoselov
I found such problems with materials for LOD elements on Unreal Engine.
Some small meshes disappear when the LOD is formed, so the materials are shifted by one or more positions and begin to display incorrectly.
To fix this you need to:
  • reassign all materials in the UE editor,
  • or disable LOD in the UE editor, then
  • or initially fix the assembly that is offered by KitBush3D.
Such problems came across in all the kits that I saw from KitBush3D for Unreal Engine.