iOS keyboard appears without a reason on app start

I am developing an app on iOS, with stock Qt 6.3.0 and testing with a ten-inch iPad.

As soon as the application gets past the launch screen (static image defined in the app launch storyboard), the iOS keyboard jumps up and covers nearly half of the screen. This happens on every app start, without any interaction from the user. I condensed the problem down to the minimal app below.

int main(int argc, char **argv) 
{
  QApplication app(argc, argv);
  QWidget * dummyWidget = new QWidget();
  dummyWidget->setFocusPolicy(Qt::NoFocus);
  dummyWidget->show();
  dummyWidget->raise();
  return app.exec();
}

 I do not see any reason why the app would open a keyboard at all.