Please fix this problem ASAP Microsoft.
If a Mixed Reality Headset is connected directly to the Surface Book's USB 3.0 ports, Windows 10 is not able to recognize the device.
If you use a USB 3.0 Hub, then Windows 10 is able to recognize the Headset.
Something is clearly messed up with the USB 3.0 port drivers on the Surface Book.
I am using a HP Mixed Reality, but this seems to be a general problem: https://forums.hololens.com/discussion/8040/getting-a-usb-device-not-found-when-plugging-my-acer-into-my-surface-book