Buttons in DialogButtonBox loose text label under certain conditions

import QtQuick 2.13
import QtQuick.Window 2.13
import QtQuick.Controls 2.10


Page {
    id: page
    visible: true
    title: qsTr("Hello World")

    Button {
        anchors.centerIn: parent
        text: "Open dialog"
        onClicked: dialog.open()
    }

    Dialog {
        id: dialog
        parent: page
        modal: true
        closePolicy: Popup.CloseOnEscape | Popup.CloseOnPressOutside

        x: (parent.width - width) / 2
        y: (parent.height - height) / 2

        title: "Test"

        Label {
            text: "Test"
        }

        footer: DialogButtonBox {
            Button {
                text: "Btn 1"
            }
            Button { // Adding this button makes the text labels disappear
                text: "Btn 1"
            }
        }
    }
}