UWP apps on Xbox One do not go higher than 55 frames per second unless the pointer is moved once per unsuspended state. If mouse mode is disabled altogether, it is still capped at 55.

Since updating WinJS to 4.4.5, the pointer has to be moved once per "frame". That's due to the pointer-down state no longer being stuck.

Pointer-down seems to set something off that allows the app to run at full speed. It should be able to do this without the presence of a pointer.

Example:

MouseTest3.zip