Editable SpinBox's text input doesn't have focus when the SpinBox is focused

import QtQuick 2.9
import QtQuick.Controls 2.0

ApplicationWindow {
    id: window
    visible: true
    width: 640
    height: 600

    onActiveFocusItemChanged: print(activeFocusItem)

    SpinBox {
        focus: true
        editable: true
    }
}

#include <QApplication>
#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QWidget widget;
    widget.resize(400, 400);
    QSpinBox *spinBox = new QSpinBox(&widget);
    widget.show();
    return app.exec();
}