Physics causes material rendering error

[echadwick-artist]

Sample file here:
KhronosGroup/glTF-Sample-Assets#256 (comment)

https://github.khronos.org/glTF-Sample-Viewer-Release/physics/

The materials on the balls start to render oddly, after the balls fall into the trough below the wheel. They start off OK if you Reset the physics (shown at left), but during simulation they get very odd reflections (shown at right).