How to reproduce:
1. Create a new Unity project and UI Document in it
2. Open the UI Document
3. Add "RadioButtonGroup" to the Canvas
4. Add "RadioButton" by dragging it on the "RadioButtonGroup" in Canvas
5. Observe the "RadioButton" and then select the "RadioButtonGroup" in the Hierarchy
6. Observe the Canvas

Expected results: The "RadioButton" doesn't disappear
Actual results: The "RadioButton" disappears 

Reproducible with: 2023.2.0a18, 6000.0.28f1, 6000.1.0a5
Not reproducible on: 2021.3.46f1, 2022.3.53f1, 2023.2.0a17

Reproducible on: Windows 10, macOS Sequoia 15.0.1 (M1)

Notes:
- Saving the project makes "Radio Button" appear
- Sometimes the "Radio Button" disappears right after adding it, in this case, it should be dragged specifically on the text of "Radio Group" or near it (depends when the "Radio Button" disappears)