UI Builder Spacing/Border widgets are missing labels

Unity: UI Toolkit Framework

6.0.X

6000.0.0b11 onwards

2023.2.X

2023.2.18f1 onwards

Steps to reproduce:

1. Open the UI Builder

2. Add and select a VisualElement

3. Notice the Spacing and Border widgets are missing labels to edit values.

Actual results: Labels are missing

Expected results: Labels are visible and editable

Reproducible with versions: 2023.2.18f1, 6000.0.0b14