R6

If neither your mouse nor keyboard are registering on your Xbox, it is usually the cable that is connecting your Xbox controller.

The required cable is a charge and sync cable. You can quickly test to see if you have one of these by having your controller off and connecting it directly to your Xbox (bypassing the K2). If the controller turns on by itself WITHOUT needing to press the home button, it is a charge and sync cable. If the controller just vibrates and requires you to press the home buttons after connecting it to your Xbox, it is NOT a charge and sync cable.

Now, if you have confirmed that you have the proper cable by conducting the test above, check for compatibility for your mouse and keyboard. You can do this by only having one connected at a time (either mouse or keyboard) and check to see if you are successfully able to map keys and/or mouse clicks on the K2 app. If you notice that one or the other is not registering, it is likely to be an incompatible mouse/keyboard.