@Fr3dY2
Your problem is from hitting your bandwidth cap and your game is waiting patiently for packets to arrive. If you can monitor your bandwidth in real time you will probably see you are constantly hitting the maximum when you experience these spikes.
When your ping is high and stable you're able to interact with the game in a different state than other players, ie shooting someone who might appear in front of you in your version of the game, but they have already passed around a wall in their version of the game.
Community Manager
