I just upgraded my project from 4.15.2 to 4.16.0. I have a pawn based off of the sample motion controller pawn. When I enter VR preview everything works correctly the first time. However the second time I activate VR preview the motion controllers no longer see their tracked position and end up sticking to a point offset from the vr camera (hand rotation still works). I am using Oculus Touch and Oculus runtime 1.15.
Any resolution for this issue? I have been experiencing the same thing.
For my case, my hand offsets are set if IsHeadTrackingAllowed() and HasValidTrackingPosition() are both true. However, on Oculus in editor, somehow these 2 booleans fail after initial VR preview. So I special cased Oculus and as long as GEngine->HMDDevice.IsValid() and it is Oculus, I setup my hands and it works for my case.