"Low", "Medium" & "High" properties dropdown icon not clickable under the "Lighting Quality Settings" in the Inspector, refer the attached video.

Steps to repro:
1. Create a new project with HDRP Template
2. Project > Create > Rendering > High Definition Render Pipeline Assets
3. Inspector > Lighting Quality Settings
4. Screen Space Ambient Occlusion/Contact Shadow > Low/Medium/High

Actual Result:
Low/Medium/High dropdown icon is not clickable

Expected Result:
Low/Medium/High dropdown icon should be click and expand

Note: "Lighting Quality Settings" is introduced in Unity 2019.3.0f2 and 2020.1.0a1 with HDRP package version 7.1.6

Reproducible in:
2020.1.0a24, 2020.1.0a1, 2019.3.2f1, 2019.3.0f2

Package version found: 7.2.1, 7.1.8, 7.1.7, 7.1.6

Workaround: On clicking Low/Medium/High properties dropdown name, the dropdown get expand

Environment:
Windows 10 and macOS 10.14