How to reproduce:
1. Create a new Unity project and import the attached "ShadowShape2DProvider" Script
2. In the Hierarchy, right-click -> Create Empty
3. In the Inspector, add the "Shadow Caster 2D" Component
4. Change the "Casting Source" to the "Simple Shadow Provider"
5. Observe the Shadow Caster Overlay in the Scene view
Expected results: The "Edit Shape" button is disabled
Actual results: The "Edit Shape button can be clicked and it shape editing is instantly closed
Reproducible with: 6000.5.0b5, 6000.6.0a3
Can't test with: 6000.0.73f1, 6000.3.14f1. 6000.4.4f1 (No such feature)
Reproducible on: macOS Tahoe 26, Ubuntu 24
Not reproducible on: No other environment tested