QML Map pinch gesture ignored on QGraphicsScene

The application is complex: it has QMainWindow with QGraphicsScene and QGraphicsProxyWidget. This widget contains QQuickWidget in which the QML Map is displayed. This structure is mandatory and cannot be changed.

In the map only Pan and Flick gestures work. No any dual-finger gestures as Pinch or Tilt are send to the object. When using two fingers on the map it receives them as one finger touch and processes movement as Pan.

QML code includes

            gesture.enabled: true
            gesture.acceptedGestures: MapGestureArea.PanGesture | MapGestureArea.PinchGesture

in Map object. The QMainWindow does not have it's own event processing. It does not grabGesture(Qt::PinchGesture). Adding this grab to MainWindow code changes nothing.