Reproduction steps:
1. Open the user's attached project "MaterialEditorBugs.zip"
2. Select the SampleScene.scenetemplate asset located in "Packages/My Package with Templates/Templates/" in the Project window
3. Change the Scene Template Pipeline to "None" in the Inspector window
4. Press CTRL+S

Expected result: The Inspector window is disabled after step 2 and step 3 cannot be performed
Actual result: The Inspector window is not disabled and a warning is thrown after step 4:
"The package cache was invalidated and rebuilt because the following immutable asset(s) were unexpectedly altered:
Packages/com.my.package/Templates/SampleScene.scenetemplate
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler ()"

Reproducible with: 2020.3.35f1, 2021.2.0a13
Not reproducible with: 2021.2.0a14, 2021.3.3f1, 2022.1.2f1, 2022.2.0a15
Could not test with: 2019.4.39f1 (Could not import asset due to errors and GUID conflicts)

Reproducible on: macOS 12.0.1