Text of a Button that's in a Layout doesn't render at startup

import QtQuick 2.7
import QtQuick.Layouts 1.3
import QtQuick.Controls 2.3

ApplicationWindow {
    id: window
    visible: true
    width: 400
    height: 680

    ColumnLayout {
        anchors.fill: parent
        anchors.margins: 8
        spacing: 20

        Slider {
            id: controlWidthSlider
            from: 1
            // Setting value with a binding works
//            value: button.implicitWidth
            to: 200
        }

        Slider {
            id: controlHeightSlider
            from: 1
//            value: button.implicitHeight
            to: 100
        }

        // Using a plain item works
//        Item {
//            id: controlWidthSlider

//            property real value
//        }

//        Item {
//            id: controlHeightSlider

//            property real value
//        }

        Component.onCompleted: updateValues()

        function updateValues() {
            controlWidthSlider.value = button.implicitWidth;
            controlHeightSlider.value = button.implicitHeight;
        }

        Rectangle {
            id: button
            implicitWidth: Math.max(100, textItem.implicitWidth)
            implicitHeight: Math.max(40, textItem.implicitHeight)
            color: "grey"

            property real leftPadding: 10
            property real topPadding: 10
            property alias text: textItem.text

            Layout.preferredWidth: {
                controlWidthSlider.value
            }
            Layout.preferredHeight: {
                controlHeightSlider.value
            }

            Connections {
                target: textItem
                onWidthChanged: print(textItem.width)
            }

            Text {
                id: textItem
                text: "Button"
                x: button.leftPadding
                y: button.topPadding
                width: button.width - button.leftPadding * 2
                height: button.height - button.topPadding * 2
                elide: Text.ElideRight

                Rectangle {
                    anchors.fill: parent
                    color: "transparent"
                    border.color: "darkorange"
                }
            }
        }
    }
}