How to reproduce:
1. Create a new Unity project
2. Open UI Builder and create any element
3. In the UI Builder Inspector, under the "Transition Animations", click "Add Transition" for a few times
4. Observe the results
Expected result: All created transitions are either expanded or collapsed
Actual result: Some transitions are created collapsed and some expanded
Reproducible with: 6000.0.81f1, 6000.3.21f1, 6000.5.7f1, 6000.6.0b7, 6000.7.0a4
Reproducible on: macOS Tahoe 26 (M1)
Not reproducible on: No other environment tested