macOS: Clicking on a menu item which opens a submenu erroneously closes menu

#include <QApplication>
#include <QMainWindow>
#include <QMenu>
#include <QMenuBar>

int main(int argc, char **argv)
{
    QApplication application(argc, argv);

    QMenu testMenu(QStringLiteral("TestMenu"));
    QMenu *subMenu = testMenu.addMenu(QStringLiteral("SubMenu"));

    QAction *subMenuAction = subMenu->addAction(QStringLiteral("SubMenuItem"));

    QMainWindow mainWindow;
    mainWindow.setWindowTitle(QStringLiteral("Test Window"));
    mainWindow.menuBar()->addMenu(&testMenu);
    mainWindow.show();

    return application.exec();
}