[REG 6.1.0->6.1.1] DragHandler inside Dialog does not work

import QtQuick
import QtQuick.Window
import QtQuick.Controls

Window {
    id: window
    width: 640
    height: 480
    visible: true

    Dialog{
        id: dialog
        width: 500; height: 500
        Rectangle{
            width: 400; height: 400;
            Rectangle{
                id: rect
                color: "red"
                width: 20;
                height: 20;
            }
            DragHandler{
                target: rect
            }
        }
    }
    Button{
        text: "open Dialog"
        onClicked: dialog.open()
    }
}