MouseArea in a ApplicationWindow's background can not be hovered since 6.9.0

import QtQuick
import QtQuick.Controls

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

    background: Rectangle {
        MouseArea {
            anchors.fill: parent
            hoverEnabled: true
            onPositionChanged: {
                console.log("pos: " + mouseX + ", " + mouseY)
            }
        }
    }
}