my physgun only works on props

every time i pick up a prop, it works completely fine, but if i try to pick up a car, or a ragdoll, i can't. i've tried everything i could think of, disabling all my mods, verifying game files, uninstalling and reinstalling, but nothing works. it's only on my singleplayer servers, too. on multiplayer, it works as it should, but when i'm in singleplayer, it sucks for some reason.