Streaming levels lighting problem

Hello everyone,

I need help to use streaming levels. I don’t really understand the lighting logic behind.
Here is my problem :

  • My level is made with 4 streaming levels, under the persistant, which are 4 villas.
  • In my persistant I’ve put all the base architecture geometry (and doors and windows which are blueprints), my environment lighting (hdri backdrop + directionnal light, all movable), and some static point lights.
  • In each of the streaming levels (villaA, B, C, D) I’ve put everything related to the inside of the villas : lights (movable) and static mesh actors (most are static).

This is made for performance issue for archviz visit.

I build my lighting when everything is displayed under my persistant.

But when I hide some of the streaming levels, I get blue lighting artifacts on my objects (I think it does only on movable objects).

See screenshots : We are in villaA. When everything is displayed it’s allright, but as soon as I unload villaB I get the artifacts.
I get no error saying I need to rebuild though.

Even if I cant understand why it could help, I tried to move the lights from persistant to a separate streaming level but I still get the glitch.

What’s the logic behind? What I did bad? How to fix this? Any idea?

Hope someone can help. Thank you very much to read me.