Lagging by running on props while hosting a multiplayer Local/Peer-To-Peer Server.

The problem is, when I run on Props, wich are angled, my Physicsgun and all other guns I use make weird motions and my movement becames laggy. HELP ME PLEASE! :frowning:
I was putting out all my Addons and was changing the level like 20 times, than I tryed to reinstall my game ( nothing changes).

(Sorry for my bad English [I am German])

Thanks in advance for the Help!