How to reproduce:
1. Open the attached project “IN-136022”
2. Open the “SampleScene”
3. In the Hierarchy, select the “Light 2D” GameObject
4. In the Inspector, turn off Shadow Strength inside of the Volumetric dropdown
5. Observe the Game View

Actual result: The shadow coming from the “Square” GameObject does not change
Expected result: The shadow coming from the “Square” GameObject gets lighter

Reproducible with: 2023.3.0a18, 6000.0.70f1, 6000.3.10f1, 6000.4.0b11, 6000.5.0a8
Not reproducible with: 2023.3.0a17

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Note: Enabling “Compatibility Mode (Render Graph disabled)” prevents this issue from occurring