I have found the solution !
In the function editorEnableMapPreview
Replace the following line:
this._editorConfig["phantom"]["handle"] = on(this.map, 'mouse-move, mouse-out, mouse-over', lang.hitch(this, function (evt) {
By this line :
this._editorConfig["phantom"]["handle"] = on(this.map, 'mouse-move, mouse-out', lang.hitch(this, function (evt) {
mouse-over is not necessary