disappearing

Hey guys, I've been having an issue with a recent map I've been working on where displacements will disappear. I can create displacement brushes, but as soon as I modify the displacement, it will disappear ingame. I'm just simply using a medium-sized level 3 displacement that seems not to work...

Heyo. I got some problems with maps again. When I approach the saws, they disappear. The room with the saws in question are separated with an area portal from other rooms, yet, the saws render when the room its in doesn't. I tried to fix this by expanding the visleaf the saws are...