Been bitching about this forever, glad people finally know what I’m talking about.
There seems to be some kind of intentional additional turncap which triggers whenever you move the mouse left, right and then left again. (Or right, left right; up, down up…) However, it’s very easy to unintentionally trigger the turncap with microscopic movements which are hard to prevent.
As Monsteri pointed out, the patch likely changed something hardware related.
Like Kreittis, I’ve also been using a G400(s).