QT SystemTrayIcon onActivated not working

app.qml

import QtQuick 2.8
import QtQuick.Layouts 1.0
import QtQuick.Controls 2.1
import Qt.labs.platform 1.0
import QtQuick.Dialogs 1.2

ApplicationWindow {
    id: appWindow

    width: 50
    height: 50
    visible: true
    title: "test"

    onClosing: {
        close.accepted = false;
        this.visible = false;
    }

    SystemTrayIcon {
        id: tray
        visible: true
        iconSource: "icon.png"
        iconName: "icon name"
        tooltip: "tooltip"

        menu: Menu {
            id: menu

            Menu {
                title: "menu again"
                enabled: true

                MenuItem {
                    text: "number 1"
                }
                MenuItem {
                    text: "number 2"
                }
            }
            MenuItem {
                text: "Exit"
                onTriggered: {
                    Qt.quit();
                }
            }
        }

        onActivated: {
            // this should not be undefined
            // https://doc.qt.io/qt-5/qml-qt-labs-platform-systemtrayicon.html#activated-signal
            console.log(reason);
        }
    }
}

icon.png

main.py

import sys

from PyQt5.QtCore import QUrl
from PyQt5.QtQml import QQmlApplicationEngine
from PyQt5.QtWidgets import QApplication


if __name__ == "__main__":
    qapplication = QApplication(sys.argv)
    qapplication.setQuitOnLastWindowClosed(False)

    qwindow = QQmlApplicationEngine()
    qml_url = QUrl("app.qml")

    qwindow.load(qml_url)
    qapplication.exec_()