Unsolved QML ToolBarStyle hides Android Menu (Qt 5.5.1)

[bchimp]

Here is basically some cut and paste QML from the documentation... an Application window with a MenuBar and a ToolBar. Run it for Desktop, it works fine. Run it on android it works fine (the menu bar is integrated on the right of the toolbar.) However, when I add the ToolBarStyle to change the background of the toolbar, the menu is gone under android. This has got to be something simple, I've tried a gazillion googles and different permutations, but no joy. Has anyone got a clue on this one?

import QtQuick 2.3
import QtQuick.Controls 1.2
import QtQuick.Layouts 1.1
import QtQuick.Controls.Styles 1.4

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("&Open")
                onTriggered: console.log("Open action triggered")
            }
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
            
        }
    }
    
    toolBar: ToolBar {
         // THIS STYLE CAUSES ANDROID MENU TO DISAPPEAR
        style: ToolBarStyle {
            background: Rectangle {
               color: "green"
            }
        }
        RowLayout {
            anchors.fill: parent
            ToolButton {
                text: "foo"
            }
        }
        
    }
   
    Label {
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }
}

[bchimp]

ok this appears to be the same problem as this:
https://forum.qt.io/topic/57647/qml-change-toolbar-color-one-style-property-only

not really "solved", but at least some pointers in that previous post.