Steps to reproduce:
1. Create new Unity project using empty URP 3D Template
2. In Inspector window create Box Volume GO (Volume > Box Volume)
3. Press “New” button to create a new Volume in Inspector window
4. Once Volume is created, press “Add Override”
5. Add “Adaptive Probe Volumes Option”
6. Press on kebab menu button on “Adaptive Probe Volumes Option” Override
7. When menu opens press on “Move to Top”, “Move Up”, “Move Down”, “Move to Bottom” and observe

Actual results: Override can be moved/menu elements can be selected when only one override is added
Expected results: Menu items to move override should be disabled when only one override is added

Reproducible with versions: 6000.0.60f1, 6000.2.8f1, 6000.3.0b6, 6000.4.0a2

Tested on (OS): Windows 11, macOS Silicon Tahoe 26.0 (M1)