Steps to reproduce:
1. Create a new HDRP default template project
2. Build the project
3. Navigate to Project Settings-> HDRP Default Settings-> Lighting

Expected results: All of the Options are available to customize
Actual results: Under Fog option Volumetrics and reprojection is grayed out

Reproducible with: 2020.2.0b8(10.1.0), 2020.2.2f1(10.2.2), 2021.2.0a3(11.0.0)
Not reproducible with: 2019.4.18f1(7.5.2), 2020.2.0b8(10.0.0 - preview27)

Note:
- Only reproduces if creating a default HDRP template project, installing the HDRP package on an empty project does not reproduce the issue
- The grayed out Volumetric options cannot be enabled
- A video is attached in the edit field