Plutonium

I recently downloaded plutonium again and got a couple of my friends to download it as well. My game is perfectly fine but my friend on the other has a problem. Whenever he ADS he moves super slow. Him and I compared side by side and I move a lot faster while ADS (we were using the same class setup) maybe some setting he needs to change? Also I was trying to play zombies with my buddies and couldn’t figure out how to do it. I get into a zombies match and when they put in (connect (my ip)) it puts them in the game and instantly kicks them out? We can play multiplayer custom games just fine though?