Unity OnMotionEvent not returning rotation


I am using Bridge Engine 1.0 (BridgeEngine.unitypackage) in Unity and I have noticed that the OnMotionEvent is called with position and orientation. The position is being updated as the structure sensor moves however the orientation never changes. I would assume that as you turn the structure sensor that it would deliver an updated rotation in the OnMotionEvent. What am I missing here? Is this a bug?

I am using Unity 2017.3.1f1, iOS 11.4 and xCode 9.3 and using an iPad Air 2.