Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Install the Splines package (com.unity.splines)
3. Create a new Square Spline (GameObject > Spline > Square)
4. Select the newly created Square Spline in the Hierarchy window
5. Click on the "Spline 0" foldout name
6. Observe the "Spline 0" foldout
7. Click on the "Knot [0]" foldout name
8. Observe the "Knot [0]" foldout
9. Click on the "Object Data" foldout name
10. Observe the "Object Data" foldout
11. Add an element to the Object Data
12. Click on the added element's foldout name
13. Observe the added element's foldout name

Actual results: Some foldouts open when clicked on name, some don't, this behavior is inconsistent

Expected results: All foldouts should open when clicked on the foldout name, not just the triangle icon

Reproducible with versions: 2.7.2 (6000.0.44f1, 6000.1.0b10), 2.8.2 (6000.0.62f1, 6000.2.12f1, 6000.3.0f1, 6000.4.0a5, 6000.5.0a1)

Tested on (OS): MacOS Tahoe 26.0.1, Windows 11