Controllers not appearing in WebXR session via streamed PCVR (Virtual Desktop)

PlayCanvas XR input events not firing despite working native WebXR

Environment

• Chrome 143.0.7499.170 (64-bit)
• Meta Quest 3 connected to PCVR via Virtual Desktop 1.34.14
• Repro: WebXR Tracked Controllers tutorial

Steps to reproduce

1. Connect Quest 3 to PC using Virtual Desktop
2. Open the tutorial project in Chrome
3. Enter XR session — headset tracking works, VR renders correctly
4. Controllers do not appear in the scene

Expected: Controllers visible and tracked in VR

Actual: VR session starts correctly but controllers never appear

Additional context

Works in: Quest 3 native browser (controllers appear correctly)

Broken in: Chrome on PC via Virtual Desktop

Investigation

• app.xr.input.on('add', fn) callback never fires
• Controller position via native WebXR API does work
• Console shows polyfill errors (unknown if related):

Uncaught TypeError: Cannot set properties of undefined (setting 'WebXRPolyfill')
Uncaught ReferenceError: WebXRPolyfill is not defined

• [Source of failing polyfill patch](https://launch.playcanvas.com/api/assets/files/scripts/webxr-polyfill/webxr-polyfill-patch.js?id=35049907&branchId=fea7377c-8461-49a9-9673-fa8b511cea3d)

Not yet tested

• Quest Link (wired/Air Link)

Reproduce the WebXR Tracked Controllers tutorial with Quest 3 streaming through Virtual Desktop, then inspect the reported WebXR polyfill errors and webxr-polyfill-patch.js. Compare the missing app.xr.input.on('add', fn) event with the working native WebXR controller position. Done means controllers appear and are tracked in the streamed PCVR session without the reported failures.