Reproduction steps:
1. Open the 'serverBuildMaterialsIssue' project
2. Open the 'Sample' Scene
3. Enter Play mode
4. Observe the printed results in the Console
5. Go to the 'File -> Build Settings'
6. 'Build and Run' the project in 'Server Build' mode
7. Observe the printed results in the Console

Expected result: the printed material properties are correct (RGBA(0.484, 0.594, 0.266, 1.000))
Actual result: the printed material properties are incorrect (RGBA(0.000, 0.000, 0.000, 0.000))

Reproducible with: 2020.1.0a18, 2020.1.28f1, 2020.2.6f1, 2020.3.24f1
Not reproducible with: 2019.4.33f1, 2020.1.0a17
Could not test with: 2021.2.5f1, 2022.1.0b1 (https://issuetracker.unity3d.com/issues/dedicated-server-support-for-windows-is-not-installed-error-in-build-settings-window)

Note: reproducible only on Windows