2) Log in to your router, and check the currently logged in devices on the management page. Get a list (List 1) of all the connected network devices in your home.
2) Enable the mobile app (Fusion Health), make sure the phone and the device are on the same network segment and connected to WIFI
3) Log in to the router and check the currently logged in devices on the management page. You'll get a second list (List 2) containing the S7, as well as other network devices in the house.
4) Compare the two lists, and the extra MAC is for the S7.
Because different routes have different management pages, I won't list them all, but they are similar. If you have any questions, you can consult the route manufacturer.