Application crashes on macOS when QMessageBox is shown from QML signal handler while Behavior/Animation is running

ApplicationWindow {
  visible: true
  width: 640
  height: 480
  title: qsTr("Hello World")

  Component.onCompleted: {
    rect.opacity = 1
  }

  Rectangle {
    id :rect
    anchors.fill: parent
    color: "grey"
    opacity: 0
    visible: opacity > 0

    // this leads to a crash if the animation below is running and openMessageBox is executed
    onVisibleChanged: myGlobalObject.openMessageBox()

    // comment this behavior and the messagebox will work
    Behavior on opacity {
      NumberAnimation { duration: 1000 }
    }
  }
}

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <myglobalobject.h>

int main(int argc, char *argv[])
{
#if defined(Q_OS_WIN)
  QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif

  QApplication app(argc, argv);
  QQmlApplicationEngine engine;

  // add context property for global object
  MyGlobalObject *obj = new MyGlobalObject();
  engine.rootContext()->setContextProperty("myGlobalObject",obj);

  // run qml
  engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
  if (engine.rootObjects().isEmpty())
    return -1;

  return app.exec();
}

#ifndef MYGLOBALOBJECT_H
#define MYGLOBALOBJECT_H

#include <QObject>

class MyGlobalObject : public QObject
{
  Q_OBJECT
public:
  explicit MyGlobalObject(QObject *parent = nullptr);

signals:

public slots:
  void openMessageBox();
};

#endif // MYGLOBALOBJECT_H

#include "myglobalobject.h"
#include <QMessageBox>

MyGlobalObject::MyGlobalObject(QObject *parent) : QObject(parent) { }

void MyGlobalObject::openMessageBox() {
  QMessageBox msgBox;
  msgBox.exec();
}