How to reproduce:
1. Open the user's attached project
2. Select "Game Manager" in the Hierarchy window
3. Click on the "Ground Material" field in the Inspector window
4. Click "Ground" Material in the "Select Material" window
5. Enter Play Mode
6. Open the "Scene view" window (Window>General>Scene)
Expected results: There are no grid lines displayed over game objects in the Scene view
Actual results: There are grid lines displayed over game objects in the Scene view
Reproducible with: 6000.0.7f1
Could not test with: 2021.3.39f1, 2022.3.33f1 (compilation errors in the Console window)
Reproducible on: Windows 10 22H2
Not reproducible on: No other environment tested