mixed reality mode is built into unity by default unless the developer disables it. In the game it works except once activated, there is no cursor on the wall when you point at it. Maybe this is related to the two right hands? I'll post a video demonstrating this if it'll help.
If it's a built-in feature, then it's probably interfering with the UI pointer system being used - if you can point the camera/view at a menu, does a pointer show up?
If it's doing what I think it's doing, I might be able to fix it pretty quickly; I'll take a look at the code and see if I can get something working in the mean time.