MapItemView is not updating upon model dataChanged signals

[Charby]

I can't get having a MapItemView updated whenever data are changed inside the model.
The MapItemView is well behaving when a new entry is added to the model but it is not reflecting the changes when an existing entry has been modified.

The model I have used is a QAbstractListModel based model. The model is working correctly when used together with a ListView : every changes in the model (new entry or modification of an existing entry) are showed in the ListView.
I first experienced this with Qt 5.4 but it is the same with Qt5.5.

To demonstrate my issue, please find below a small example with a MapItemView and a ListModel (i.o a C++ model). What does I miss ?

import QtQuick 2.4
import QtQuick.Window 2.2
import QtLocation 5.3
import QtPositioning 5.0

Window {
    visible: true
    width : 1024
    height:768

    Map {
       id: map
       anchors.fill: parent
       anchors.margins: 50
       plugin: Plugin{ name:"osm";}
       center: QtPositioning.coordinate(47.1, -1.6)
       zoomLevel: map.maximumZoomLevel


       MapItemView{
           id:mapItemView
           model: dummyModel

           delegate: MapQuickItem {
              //anchorPoint:
              id:delegateMQI
              rotation: model.Azimuth
              sourceItem: Rectangle{
                  id:defaultDelegate
                  width:32
                  height:32
                  radius:16
                  opacity: 0.6
                  rotation:Azimuth
                  color:Color

                  Text{
                      text: Azimuth
                      anchors.centerIn : parent
                  }

              }
              coordinate: QtPositioning.coordinate(Latitude,Longitude)
          }

       }
       MouseArea{
           anchors.fill: parent
           onClicked:
           {
               //Modify an item
               var newAzim = Math.random()*360;
               dummyModel.setProperty(0, "Azimuth", newAzim);
               //Check modification
               console.log("Azim:" + dummyModel.get(0).Azimuth );
               dummyModel.setProperty(0, "Color", "blue");

               //add a new item
               dummyModel.append({"Latitude": 47.05 + Math.random() *0.1, "Longitude":-1.65 + Math.random() *0.1, "Azimuth":0, "Color":"red"})
               console.log("Nb item:" + dummyModel.count );

               map.update();
               map.fitViewportToMapItems();

           }
       }
    }
    ListModel{
        id:dummyModel
        ListElement {
            Latitude: 47.1
            Longitude: -1.6
            Azimuth: 10.0
            Color:"red"
        }
    }
}

[Charby]

Has any one experienced the same problem ? Any idea of a possible workaround ?
Thanks for your help.