Ok so.. I was playing GTA V today when suddenly the game started stuttering everytime I moved the mouse. I tried restarting the game, tried different games and even rebooted the system but the problem persisted. Eventually I went to iCUE and changed the mouse's polling rate from 1000Hz to 500Hz and that fixed the problem. Could this be an issue with my motherboard's USB controller or did the mouse deside it can't do 1000Hz polling rate anymore?