bug, need help

So yeah, today, when i went on my cider server i found out something.
When you use a weapon (its only with weapons weirdly enough) and get killed, you still have that weapon in your inventory while it should be gone.
The player who killed me could pickup the gun but the icon didnt dissapear in my inventory.
Then when i click on it it says “you do not own this weapon” and it still doesnt dissapear.

I dont got any error messages, neither in console or rcon. And I dont got that bug on singleplayer.