Steps to reproduce:

1. Create a prefab with a serialized property field that accepts a GameObject
2. In the Hierarchy, select the Prefab
3. Drag a non-persistent (scene) GameObject into the property field e.g sphere
4. Observe that a transparent blue override bar appears (expected)
5. Drag a persistent GameObject (e.g., another prefab) into the same field
6. Reverse the order, start with a valid persistent GameObject, then drag a non-persistent one
7. Observe the override bar

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Actual results: The override bar does not update its transparency when switching between valid and invalid GameObjects. Stays transparent when it should be solid

Expected results: The override bar should dynamically update, switching from transparent to solid blue (or vice versa) based on whether the object is valid for overriding

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Reproducible with versions: 2022.3.62f1, 6000.0.52f1, 6000.1.11f1, 6000.2.0b9

Can't test with this version: 2021.3.53f1 (the bar doesn't change for both objects)

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Tested on (OS): macOS 15.6 Silicon