iOS: F-key Events Not Delivered

To reproduce:
1. Connect a Bluetooth keyboard to a device;
2. Run a Qt application with implemented:
event
keyPressEvent
keyReleaseEvent
inputMethodEvent

Either place printouts or break-points in the functions;

3. Use the keyboard and observe that pressing
letters and digits generates key-event that are
properly delivered;

4. Try now Fn-F1, Fn-F2, ... Fn-Fy-1, Fn-Fy keys where Y is from 1 to 12
Observe, that there are no events delivered neither
to keyPressEvent nor to inputMethodEvent;

5. Proceed with steps 1-4 by using the setup with an Android device.
Observe that the F-key events are properly delivered.