Twice QWidget::event TouchBegin instead one

[giancarlo.fir]

I wrote an application for raspberry with qt 5.3, raspbian jessie and a 7-inch touch screen.
In my application I need to override the QWidget::event method. And everything was worked ok.
My problems start when I ported my code to raspbian stretch with the qt 5.7.1.
Now my code doesn't work because the QEvent::TouchBegin event is sent twice time.
Do you have any suggestions?

Code

bool Zone::event(QEvent *e)
{
	if (e->type() == QEvent::TouchBegin) {
		qDebug("TouchBegin");
		.........
		return true;
	}
 
	if (e->type() == QEvent::TouchEnd) {
		qDebug("TouchEnd");
		.....
		return true;
	}
 
	if (e->type() == QEvent::MouseButtonPress) {
		qDebug("MouseButtonPress");
		.....
		return true;
	}
 
	if (e->type() == QEvent::MouseButtonRelease) {
		qDebug("MouseButtonRelease");
		.......
		return true;
	}
	return QWidget::event(e);
}

bool Zone::event(QEvent *e)
{
	if (e->type() == QEvent::TouchBegin) {
		qDebug("TouchBegin");
		.........
		return true;
	}

	if (e->type() == QEvent::TouchEnd) {
		qDebug("TouchEnd");
		.....
		return true;
	}

	if (e->type() == QEvent::MouseButtonPress) {
		qDebug("MouseButtonPress");
		.....
		return true;
	}

	if (e->type() == QEvent::MouseButtonRelease) {
		qDebug("MouseButtonRelease");
		.......
		return true;
	}
	return QWidget::event(e);
}

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Output
TouchBegin
TouchBegin
MouseButtonPresseds
TouchEnd
MouseButtonReleased