Hi,
It looks like the scene clearColor is not the color used to clear the screen in WebXR with multiview enabled on the Quest. Instead black is used to clear the screen.
Playground reproducing the issue with multiview (background is unexpectedly black in XR/VR): https://playground.babylonjs.com/#9K3MRA#1130
Playground showing the issue does not occur when multiview is not enabled: https://playground.babylonjs.com/#9K3MRA#1131
Thanks.