Scrolling to select hotbar doesn't work or temperamental

Holding shift and scrolling to change the selected Item in the hotbar doesn't work. Seems to only be an issue on Macs and Works fine on Windows. I've tried rebinding my keys and tried multiple servers and single player and it is a problem regardless of where I try.

 

Also if I try to scroll 1 step at a time the selected item in the hot bar will not change. Only when I scroll through a lot and fast will the selected item scroll through the hotbar