Is this a bug with OpenXR tracking in OpenXRHMD.h:145?
virtual void SetTrackingOrigin(EHMDTrackingOrigin::Type NewOrigin) override
I thought you would pass in EHMDTrackingOrigin::Stage to get the Stage tracking but you'd have to call it with EHMDTrackingOrigin::Floor counter-intuitively. `GetPlayAreaBounds(EHMDTrackingOrigin::Type)` in contrast maps Eye to View, Floor to Local, and Stage to Stage.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-127962 in the post.