Gliding cursors in game

This happens seemingly randomly, while playing, when I'm in my inventory, or playing the game normally. When I move my mouse, or pointer any way, to won't stop right away, it will keep going for a little bit, depending on how fast you moved your mouse. This doesnt happen in the settings, or in any part of the title screen, only inside a game/server. It really messed up my pvping, skills.