Attached style properties not propagating when popupType is set to popup window

import QtQuick.Window
import QtQuick.Controls
import QtQuick.Layouts
import QtQuick.Controls.Material

ApplicationWindow {
    id: window
    width: 200
    height: 200
    visible: true
    Material.foreground: togglePal ? Material.Purple : Material.Blue
    property bool togglePal: true    
    Button {
        text: "Open"
        onClicked: popup.open()
    }    
    Popup {
        id: popup
        width: parent.width
        height: parent.height
        popupType: Popup.Window
        Button {
            id: button
            text: "Toggle palette"
            onClicked: { window.togglePal = !window.togglePal }
        }
        Label { anchors.top: button.bottom; text: qsTr("Label control") }
    }
}