Problem with actors loading time

Hello everyone, im having a problem with the loading of actors in a specific situation that makes my game lag for a short period of time. I have a maze level, when the player is inside the maze it runs at 120fps mostly, but when he jumps, sudenly most of the maze (wich is made by spline actors and static meshes) becomes visible and the framerate drops to arround 15fps for an instant, then its arround 70 fps

So I was thinking, is there a way to preload actors and meshes before they become visible? (They are all in the same level) I wouldnt mind having a constant lower 70 fps instead of 120 if that prevented the lag when looking over the walls.

Maybe you can use a culling distance volumn to set the rendering distance for the actors. I think the dropping of fps is due to the rendering instead of loading. All actors in the current level are loaded when you enter this level. But it takes time to rendering the actors when you can see them on the screen.