I am using a laptop with Windows 10 Anniversary Update. I have a second monitor plugged in via an HDMI cable. The monitors have different resolutions. The one plugged into my laptop is set to 1920x1080. My laptop screen is set to 2880x1800 (It is a MacBook Pro with Retina). If I click on the Start10 button on one monitor, and then click on the Start10 button on the other, the menu appears in the wrong position on the second monitor.

In the screenshot below, I first clicked the Start10 button on the laptop monitor, and then the Start10 button on the external monitor. Notice that it appears too high on the screen:

And in the image below, I clicked on the Start10 button on the external monitor, and then on the internal monitor. Notice that it appears too low on the screen: