UE5.4 + Vive OpenXR Sample — “Unknown Motion Source *Interaction” warnings + Massive lags after first VR Preview run

Hi everyone,

I’m running into a persistent issue with the official Vive OpenXR sample project in Unreal Engine 5.4 and I haven’t been able to resolve it after extensive debugging.

Setup

  • UE 5.4

  • Vive OpenXR Sample (clean download)

  • OpenXR + Vive OpenXR plugins enabled

  • SteamVR runtime (OpenXR SteamVR)

  • Issue reproduces in a fresh project without modifications

Problem
On the first VR Preview run everything works correctly.
Hand interactions (pinch grab, etc.) behave as expected.

After stopping and running VR Preview again:

  • Grabbing or pinching causes the entire world to appear stuck to HMD movement

  • Scene becomes laggy for ~2–3 seconds

  • Then everything snaps back to normal

  • Repeats every time a new pinch/grab interaction begins

Log spam appears during this:

LogHMD: Warning: GetControllerOrientationAndPositionForTime called with motion source LeftPinchInteraction which is unknown. Cannot get pose.
LogHMD: Warning: GetControllerOrientationAndPositionForTime called with motion source RightAimInteraction which is unknown. Cannot get pose.
...

This affects:

  • PinchInteraction

  • AimInteraction

  • GripInteraction

  • PokeInteraction

Observations

  • These motion sources are defined by the Vive sample and required for interaction

  • Changing Motion Sources to standard (Left, Right, etc.) removes warnings but breaks interaction completely

  • Happens in clean project

  • Happens consistently after first run

  • Looks like pose queries fail during session reinitialization

  • Vive plugin logs show tracked devices and action sets attaching successfully

What I’ve tried

  • Verified OpenXR runtime

  • Editor restarts

  • Clean project

  • Late update toggles

  • Config overrides

  • Input action review

No resolution.

Question
Has anyone encountered this interaction-motion-source mismatch or session reinit issue with Vive OpenXR in UE5.4?
Is this a known limitation of MotionControllerComponent with custom interaction sources, or a runtime/plugin lifecycle problem?

Any insight is appreciated.

Thanks!

VIDEO:

Interaction Lag VR Preview

That error message seems to come from the base OpenXR plugin. It suggests it’s failing to call the function on the correct motion controller class from the plugin, and is falling back to the base OpenXR class.

This sounds like it could be a lifecycle issue, where it’s failing to create or initialize the FViveOpenXRHandInteraction motion controller objects for the hand interaction poses when restarting the OpenXR session.