Collision flickering

Hi guys!

I have a weird problem, where I see flickering when I use the player collision view
At first I thought it might be my fault with importing static meshes, so I started a new level
and put the collisions in manually. It worked well at first, until I added something like 10 actors into the scene,
and now I’m having the flickering again.

Above images show how my scene looks. It seems that there is a collider around the camera, which is weird as I deleted all cameras
and characters in that scene.

Any ideas?
Thanks for any help!