As noted previously, I have a new Macbook Air and I am just getting used to using Mac OS. When at my desk I am connecting the Macbook to a 32 inch BenQ monitor via a USB-C dock and because I am using the Macbook’s keyboard, the monitors are arranged in System Preferences Displays settings as vertically stacked, with the external display above the internal display. I have the external display set as the primary but what has been frustrating is that the OS X dock doesn’t automatically move up to the primary display. I cannot believe that I have to move the mouse to the bottom left of the external monitor to get the dock to move when OS X seems to be smart enough to know which menu bar is active on which display; seems to me on which ever screen the menu bar is active that is the display that should have the dock. Testing shows that the issue only seems to be with vertical stacking of the displays (so I move the mouse up/down between displays) and not when the monitors are horizontally arranged (move the mouse right/left between displays).