No movable actor when streaming the level

Hi there !
I just went into a problem using level streaming : I’ve got a persistent level in which I stream one only level. But when loading, all movable actors it contains are deleted. Any advice ?
I checked and no BP asks such a thing. Launching the level indepedently shows the actors well.

Nevermind… My bad : I have a big Sphere as a background in my persistent level and forget to disable its collision… So all my movable meshes were send out of world’s bounds because af this collision.