[Robotic Pope]

Yeah, this is caused by latency. You are getting what I call Mini Lag. Sometimes you can get it bad and nothing you fire at ever gets hit because by the time the game registers that you have fired in the correct point of sky to hit a plane the plane is now further along in their flight trajectory. What you have to do is lag lead your target. As Arcade is played at much higher speed the lag effects it much more than the realistic and sim. In arcade you might need to give your target a huge lead or guess their next turn to kill them.