Magic Mouse 2 Only Connects When Plugged In I have a Magic Mouse 2 - the type that can be connected to my laptop with a Lightning cable, and a Retina MBP 15-inch Mid 2015 running Sierra (10.12.3).

My mouse does not connect via Bluetooth. Power cycling the mouse, the computer itself, the bluetooth, and the wifi does nothing. I've also tried un-pairing the mouse as well. I followed every step of every answer on this already.

However, when I plug in the mouse with my lightning cable, the mouse is immediately recognized as my mouse, and even has a 88% charge on it. The moment I unplug the mouse, it is disconnected and unrecognizable.

Help?
It may be an issue with one of the bluetooth radios.

Can your MBP connect to other BT devices?
 - If not, you may need to get your MBP to Apple Service.

Can you connect the MM2 to a different computer via BT?
 - If not, you may need to get your MM2 to Apple Service.

If you can't test this yourself, you should get both units to an Apple store and let them diagnose it for you.  They are usually pretty good at root-causing such issues.