Running Windows 10 Enterprise RTM. With two monitors, after the computer goes to sleep all windows return to main monitor. When only locking the computer and waking it up again windows stay where they should be. The system has two non-sli graphics cards, however both monitors are plugged into the same card.
EDIT: the two monitors are hooked up with DP -> DP on the main monitor and DVI -> HDMI on the second monitor (monitor -> PC).
EDIT2: switched the second monitor to DVI -> DVI, problem still persists.
EDIT3: put the monitors on different, non SLI GPU's, problem still persists