Reproduction steps:
1. Open the attached project "Flickering.zip"
2. Go to the Project window
3. Select "black" Material and drag it over the "Cube" Game Object in the Scene View without releasing it
4. Drag the same "black" Material onto the "Sphere" Game Object without releasing it
5. Observe the "Sphere" Object

Expected result: "Sphere" Object Material is changed while hovering with "black" Material over
Actual result: "Sphere" Object Material flickers while hovering with "black" Material over

Reproducible with: 2020.3.19f1, 2020.3.34f1, 2021.3.1f.1, 2022.1.0f1, 2022.2.0a11
Not reproducible with: 2019.4.38f1, 2020.3.18f1

Notes:
- Reproducible with macOS
- Not reproducible with Windows
- Not reproducible if Game Objects are not touching each other