Enter event not delivered after showing & closing (context) Menu by click on outside

#if !defined(LEAVEWIDGET_H)
#define LEAVEWIDGET_H

#include <QFrame>

class LeaveWidget : public QFrame
{
    Q_OBJECT
public:
    LeaveWidget(QFrame * parent = 0, Qt::WindowFlags f = 0);

protected:
    virtual bool event(QEvent * event) override;
    virtual void contextMenuEvent(QContextMenuEvent *event) override;

private:
    void showMenu();
};

#endif //LEAVEWIDGET_H

#include "leavewidget.h"
#include <QDebug>
#include <QMouseEvent>
#include <QMetaEnum>
#include <QMenu>

LeaveWidget::LeaveWidget(QFrame * parent, Qt::WindowFlags f)
    : QFrame(parent, f)
{
    setFixedSize({200, 200});
}

bool LeaveWidget::event(QEvent * event)
{
qDebug() << __FUNCTION__ << QEvent::staticMetaObject.enumerator(QEvent::staticMetaObject.indexOfEnumerator("Type")).valueToKey(event->type());
    if (QEvent::MouseButtonPress == event->type() && Qt::LeftButton == dynamic_cast<QMouseEvent *>(event)->button())
            showMenu();
    return QFrame::event(event);
}

void LeaveWidget::contextMenuEvent(QContextMenuEvent *event)
{
    showMenu();
    QFrame::contextMenuEvent(event);
}

void LeaveWidget::showMenu()
{
    QMenu * menu = new QMenu{this};
    menu->setAttribute(Qt::WA_DeleteOnClose);
    menu->addAction(QStringLiteral("test1"));
    menu->addAction(QStringLiteral("test2"));
    menu->popup(QCursor::pos());
}

#include "leavewidget.h"
#include <QApplication> 

int main(int argc, char * argv[])
{   
    QApplication app{argc, argv};
    LeaveWidget w;
    w.show();

    return app.exec();
}