World composition

Hello, i have world with streaming levels. All levels are same sizes and identical bounds. So, after adding few static meshes / actors / characters to levels i found my world composition looks like this:

Is it normal?

composited by Picasso ))
kk, what added to levels and what can cause of this:

  • simple static meshes
  • static meshes with dynamic materials
  • Simple shapes (cubes) colored with materials
  • decals
  • Foliage (aka “foliage types”)
  • layered material (landscape painting)
  • actors based static meshes
  • Volume bounds are in zero point (pp, sound, etc.)
  • gameplay actors are same in zero point
  • map markers actors
  • Different characters

Some time ago i notice that if to add particle to level - level’s bouds will be collapsed. This way there no particles. What else can to collapse levels?