Riven mod head shot bug

[lukeyami]

I have a riven mod which needs to be unveiled but it requires 4 head shots in a single aim glide, while that is doable the latest hot-fix now wants it to be head shot kills, but every time I have tried this it does not count all 4 head shot kills it stops at three even though I have had more. I am using argon scope so I know when I get a head shot as the buff appears/resets and the enemies are low enough level they die in one hit from my weapon from that head shot.