Reproduction steps:
1. Open the attached project "HybridHDRPSamples.zip"
2. Open the "MatrixPrevious" Scene
3. Enable Pause and enter Play mode
3.a Step frames forward until the subscene is loaded
4. Open the Rendering Debugger window
5. In the Rendering tab, set Fullscreen Debug Mode to "MotionVectors"
Expected result: The Game view is black
Actual result: Motion vectors pointing away from origin are visible
Reproducible with: 0.51.1-preview.21, 0.51.0-preview.32 (2021.3.8f1)
Could not test with: 2020.3.38f1 (Various errors when downgrading/remaking the project)
Reproducible on: macOS 12.4