Broken customization

import QtQuick 2.9
import QtQuick.Controls 2.2

ApplicationWindow {
    id: window
    width: 640
    height: 480
    visible: true

    Column {
        anchors.centerIn: parent
        BusyIndicator {
            contentItem: Rectangle { implicitWidth: 20; implicitHeight: 20; color: "red" }
        }
        DelayButton {
            contentItem: Rectangle { implicitWidth: 20; implicitHeight: 20; color: "red" }
        }
        Dial {
            handle: Rectangle { implicitWidth: 20; implicitHeight: 20; color: "red" }
        }
        ScrollBar {
            size: 0.5
            active: true
            width: parent.width
            orientation: Qt.Horizontal
            contentItem: Rectangle { implicitWidth: 20; implicitHeight: 20; color: "red" }
        }
        ScrollIndicator {
            size: 0.5
            active: true
            width: parent.width
            orientation: Qt.Horizontal
            contentItem: Rectangle { implicitWidth: 20; implicitHeight: 20; color: "red" }
        }
    }
}