Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Make sure Hierarchy V2 is enabled (Unity > Settings > General > Use new Hierarchy window)
3. Install the Entities package (com.unity.entities)
4. Open the Entities Systems window (Window > Entities > Systems)
5. Click the kebab button on the right side and select "Show Full Player Loop"
6. Type something in the Search bar that would have no results ("feshjfkhesjkfhs" used in this reproduction)
7. Click the "x" button on the right side of the Search bar
8. Observe the Entities Systems window

Actual results: The Entities Systems window did not reset to its original state, showing no elements, completely empty

Expected results: The Entities Systems window resets to its original state, and is not empty

Reproducible with versions: 6000.5.0a2, 6000.5.0b2, 6000.6.0a2

Not reproducible with versions: 6000.0.72f1, 6000.3.12f1, 6000.4.1f1, 6000.5.0a1

Can’t test with versions: 2023.1.0a3 (Due to no Entities package)

Tested on (OS): MacOS Silicon Tahoe 26.3

Notes:

• Editor versions 6000.5.0a8 and below require extra steps for reproduction before step 4, which are: Open the Entities Hierarchy window, and create a new Sub-Scene, then proceed to the Entities Systems window.