Toolbar hides and could not reappear when exiting fullscreen mode in Media Player example

MacOS 13.5.1 

Qt Creator 11.0.2

Steps to reproduce:

1. Run 'Media Player Example' (the new one) and play the video in fullscreen.
2. Wait till the toolbar disappears.
3. Double-click to exit fullscreen. 

Expected: The toolbar should be visible. 

Actual: The toolbar does not appear. 

Reproducibility:  100%