How to reproduce:
1. Open the user's attached project("U2021.zip")
2. In the Project window rename "rapid.obj" to "Model.obj"
3. Rename "rapid.mtl" to "Model.mtl"
4. Notice the object retains its material
5. Reimport "Model.obj"
Expected results: After reimporting, the object retains its material because the mtl file is synced with it
Actual results: After reimporting, the object loses its material and goes out of sync with the mtl file
Reproducible with: 2018.4.29f1, 2019.4.14f1, 2020.1.13f1, 2020.2.0b11, 2021.1.0a5