Reproduction steps:
1. Open the attached project "ReproProj"
2. Open the “/Assets/Scenes/SampleScene.unity” Scene
3. Enter Play Mode.
4. Open Window > Analysis > Rendering Debugger
5. Select the Volume tab
6. Set Camera to Main Camera and Component to Post-processing/Vignette
7. Observe the Intensity row
Expected result: Graphics Settings shows the same value as the Result
Actual results: Graphics Settings shows 0
Reproducible with: 6000.0.58f1, 6000.2.6f1, 6000.3.0b2
Testing environment: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested