Delivery of mouse wheel events to QtQuick Items is erratic

import QtQuick 2.8
import QtQuick.Window 2.2

Window {
  id: window
  visible: true
  width: 800
  height: 480
  title: qsTr("Hello World")

  ListView {
    anchors { top: parent.top; bottom: info.top; left: parent.left }
    width: window.width / 2
    model: 1000
    delegate: Text { text: "List left " + modelData }
    clip: true
  }

  ListView {
    anchors { top: parent.top; bottom: info.top; right: parent.right }
    width: window.width / 2
    model: 1000
    delegate: Text { text: "List right " + modelData }
    clip: true
  }

  Text {
    id: info
    anchors { bottom: parent.bottom; left: parent.left; right: parent.right }
    text: "<ul><li>Start wheeling down in <b>left</b> list and move mouse pointer to the <b>right</b> list while scrolling is still going on." +
              "<li>Mac only: Also note that until wheeling was actually startet in the right list <b>once</b> it does not scroll or maybe just a little bit" +
              "<li>Mac only: When moving the mouse pointer back to the list where wheeling started, that list scrolls back to top and down again"

    wrapMode: Text.WordWrap
    color: "red"
  }

}