Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Create a new UI Document Asset (Assets > Create > UI Toolkit > UI Document)
3. Double click the newly created UI Document Asset to open it in the UI Builder window
4. Add a Label to the Canvas
5. Open the "Filter" foldout in the UI Builder's Inspector
6. Add 3 filters in the Filter list
7. Select the bottom filter
8. Click the "-" button to remove the selected bottom filter
9. Click the "-" button again
10. Observe the Filter list

Actual results: Nothing happens

Expected results: The next filter is removed

Reproducible with versions: 6000.3.6f1, 6000.4.0b5, 6000.5.0a5

Can’t test with versions: 6000.0.66f1 (due to no Filter list)

Tested on (OS): MacOS Silicon Tahoe 26.2

Notes:

• The "-" button gets disabled if the list is empty