I’m using the keyboard prefab with KeyboardInputField UI elements from the MixedRealityToolkit and when I select one of the KeyboardInputFields in a build I’m getting both the keyboard prefab and a system keyboard poping up. An earlier build I made using both of these was not displaying the system virtual keyboard, but I don’t know what I could have changed to cause this. I am using unity 2017.2.0p2-MRTP5 and MixedRealityToolkit for Unity 2017.2.1f1. (which is what was suggested by the Microsoft representative I talked to)
I’m creating an immersive experience and have the Unity build type set to D3D not XMAL.
I found more information on the problem here. It is a reported bug. Issues using the keyboard prefab on PC · Issue #1370 · microsoft/MixedRealityToolkit-Unity · GitHub