Brand new Dell XPS laptop with brand new Microsoft Arc Touch Mouse and Windows 10. Everything paired up fine, but frequently, the mouse would just stop working. Turning the mouse off and then on would fix it until the next disconnect. Happened every minute or two, really frustrating.
The solution was to uncheck the "Allow computer to turn off this device to save power" box under the "Power Management" tab of the "Intel(R) Wireless Bluetooth(R)" device under Device Manager>Bluetooth