Not sure if you can turn it off, but maybe I can help based on what I've seen and discovered.

The traditional crosshair almost isn't even needed. It's used as a way to "contain" the white circle visually which covers your spread. The tiny white dot that bounces around is muzzle sway and where your bullet will actually hit once you pull the trigger. It bounces more rapidly and the "spread" circle gets bigger the more fatigued, more movement, and based off of general positioning.

It threw me off at first too, and when I'm using an LMG I don't even really look at it, but for semi auto head shots while moving, the muzzle sway dot is highly necessary.