Ben bought an IOGear KeyShair KVM switcher. KVM stands for Keyboard, Video and Mouse, and is great for switching between two devices. This one is a dongle that plugs into the computer and uses Bluetooth to connect to mobile devices as well. The problem is that he can't see the mouse cursor in Windows 10, even though it's there. It's puzzling.
Leo says it may not be Windows 10, per se, but the configuration of his Surface tablet. Ben should go into the mouse settings and see what it will do. But since he has the same problem with his wife's surface, it sounds like an issue with Windows 10 pro's security settings.