QWebenginePage print resultCallback called before print finished.

Cannot print to PDF while at the same time printing on printer Microsoft XPS Document Writer

#include <QApplication>
#include <QCoreApplication>

#include <QWebEngineView>
#include <QWebEngineSettings>

#include <QPrinter>
#include <QPrintDialog>

int main(int argc, char *argv[])
{
  QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
  QApplication a(argc, argv);

  QPrinter printer;

  QWebEngineView* viewer = new QWebEngineView();
  viewer->settings()->setAttribute(QWebEngineSettings::PrintElementBackgrounds, true);

  QObject::connect(viewer->page(), &QWebEnginePage::loadFinished,
    [&](bool ok)
    {
      QPrintDialog printDialog(&printer);
      if (printDialog.exec() == QDialog::Accepted)
      {
        printer.setPaperSize(QPrinter::A4);
        printer.setPageOrientation(QPageLayout::Landscape);
        printer.setPageMargins(0, 0, 0, 0, QPrinter::Millimeter);
        printer.setFullPage(true);
         
        //print on printer
        viewer->page()->print(&printer,
          [&](bool result)
          {
            //print to pdf
            viewer->page()->printToPdf(QString("tmp.pdf"));
          });
      }
    });

  viewer->load(QUrl("http://google.com"));
  viewer->show();

  int result = a.exec();

  delete viewer;

  return result;
}