Steps to reproduce:
1. Open the attached “IN-86457_TestLabelsUpdating.zip” project
2. Open the “SampleScene”
3. Make sure you have the Project Window and Search Window opened side by side
4. In the Search Window type “p: l:architecture”
5. Select the "Cube.prefab" GameObject in the Project window
6. In the Inspector, change the Label to "Architecture"
7. Duplicate the “Cube.prefab”
8. Observe the Search Window

Expected result: Both Cube prefabs are shown in the Search Window
Actual result: Only the Duplicated Cube prefab is shown in the Search Window

Reproducible in: 2021.3.45f1, 2022.3.51f1, 6000.0.25f1, 6000.1.0a2

Reproducible on: Windows 11, macOS (Silicon)
Not reproducible on: No other environment tested