QApplication cannot catch QEvent::TabletLeaveProximity starting from Qt5.6

class Application : public QApplication{
public:
    Application(int& argv, char** argc)
        : QApplication(argv, argc)
    {}
protected:
    bool event(QEvent* event)
    {
        if (event->type() == QEvent::TabletEnterProximity){
            qDebug() << "Tablet enters proximity";
            return true;
        }
        if (event->type() == QEvent::TabletLeaveProximity){
            // this part is never entered in Qt5.6
            qDebug() << "Tablet leaves proximity";
            return true;
        }
        return QApplication::event(event);
    }
};