MacOS Sierra bug. Mouse runs irratically once you enter the rift

so, i just updated to sierra on my mac (2015 MBP Retina 8gb ram model) and frankly im flabberghasted

as all mac users know, if you move the mouse or trackpad fast enough, it causes the mouse itself to enlarge in size indicating its location to the user

now whhen i enter a summoner's rift game, this happens at the TINEST movement of my mouse. i use a logitech chaos spectrum g900 and i had NO problems like this prior to updating. i was on el capitan before

the worst part is that the movement of the mouse acting like this makes it IMPOSSIBLE to play the game

does anybody have a fix or any ideas whats going on? i know its my own fault for not checking for bugs before updating, but shy of dropping down to el capitan, is there any fixes for this irratic mouse behaviour?

ive confirm its only with league of . legends this occurs; all other games do NOT exhibit this weird mouse movement