It is mentioned in the notes here App Inventor Tutorials and Examples: Manager Screen | Pura Vida Apps... as it looks like you have missed it, let me copy it here
Current limitations of the AI Companion app:
- The close screen block triggers the Initialize event instead of the OtherScreenClosed event.
- The close screen with value block triggers both the Initialize and OtherScreenClosed events instead of only the OtherScreenClosed event.
- The close application block does not work, a message 'Closing forms is not currently supported during development' will be displayed instead.
Taifun