Steps to reproduce:
1. Create new AR Template Unity Project
2. In Hierarchy window, create new "XR -> AR Default Plane" and "XR -> AR Default Face" GameObjects
3. In Hierarchy window, select either of these two new GameObjects
4. In Inspector window, observe Mesh Renderer -> Materials -> Element 0
Expected result: A default material is set
Actual result: No default material is set
Reproducible with: 5.0.0-pre.12 (2022.2.0a17), 5.0.2 (2022.2.0b15, 2023.1.0a18)
Not reproducible with: 4.1.12 (2020.3.41f1), 4.2.6 (2021.3.13f1, 2022.1.23f1), 4.2.3, 4.2.7 (2022.2.0a16).
Reproduced on: Windows 10