I'm running Windows 10 Pro on my home laptop. I've got 2 monitors setup, the one on the laptop and 22" Acer using HDMI output.
Since 1 is set as the primary, I have the system tray on that monitor, in keeping with normal Windows conventions, I like to have all my icons on my primary monitor. For some reason, seemingly at random, normally when the system goes to sleep, Windows will move all my desktop icons to the other monitor.
I can manually pull the icons back to my primary, but it's a little frustrating and I have to believe that it's easily fixable if the causes found.
The laptop is a Sager with a i7-6700, 16 GB RAM, 256 GB SSD, 1 TB HD. I've had it happened using both the Intel graphics on the processor as well as the external Nvidia 960 video card.