aboutToQuit is not emitted when closing the desktop session

When reading in the documentation i can see that aboutToQuit is supposed to be emitted when exiting a desktop session:

This signal is emitted when the application is about to quit the main event loop, e.g. when the event loop level drops to zero. This may happen either after a call to quit() from inside the application or when the user shuts down the entire desktop session.

— https://doc.qt.io/qt-6/qcoreapplication.html#aboutToQuit

However for me aboutToQuit is not emitted when exiting my desktop session (but the signal is emitted if the user closes the window)

Please see the attached file for an example. (To determine if the signal has been emitted i write to a log file)

Only tested on XUbuntu and with PySide6