Lagging Level Streaming Volume

When I enter a streaming volume with the character in order to load another piece of map, there is a 1s/2s seconds lag which is bad for immersion. Any idea how to remove this lagging?

Also is there any way I can reset the level with the streaming volume ?. If I die inside the volume it should reset all the objects to initial positions and state.

did you find the solution?
I have the same problem

lagging was due to low FPS