Reproduction steps:
1. Open the attached “Repro“ project
2. Select the “Assets/CarInspector.cs“ Asset in the Project Browser
3. Observe the ability to reference “Inspector UXML“ Visual Tree Asset in the Inspector
4. Select the “/Assets/CarDrawer.cs“ Asset in the Project Browser
5. Observe the Inspector

Expected result: There’s a field to reference “Inspector UXML“ Visual Tree Asset in the Inspector
Actual result: “Inspector UXML” is not serialized

Reproducible with: 2021.3.35f1, 2022.3.20f1, 2023.2.12f1, 2023.3.0b9

Reproducible on: M1 MacOS 14.3.1
Not reproducible on: No other environment tested