I have a problem where items disappear in my ListView which is in a popup when I use LayoutMirroring.
Sometimes the last item disappears and sometimes the second last item, depending on the LayoutMirroring.
The bug disappears when I comment out the lines which set the contentWidth and contentHeight.

I do not understand why this is happening, does anyone have an explanation?

The code example:

import QtQuick 2.15
import QtQml 2.15
import QtQuick.Window 2.14
import QtQuick.Controls 2.15
import QtQuick.Layouts 1.15

Window {
    id: root
    property bool mirrorLayout: false

    width: 800
    height: 600
    LayoutMirroring.enabled: mirrorLayout
    LayoutMirroring.childrenInherit: mirrorLayout

    ColumnLayout {

        RowLayout {
            LayoutMirroring.enabled: false

            Button {
                text: "Open Popup"
                onClicked: popup.open()
            }

            Button {
                text: "Mirror Layout"
                onClicked: mirrorLayout = !mirrorLayout
            }

            Text {
                text: "IsMirrored:", mirrorLayout
            }
        }

        RowLayout {
            Repeater {
                model: 5
                delegate: Rectangle {
                    color: "red"
                    opacity: (5 - index) / 5
                    width: 40
                    height: 40

                    Text {
                        text: index + 1
                        anchors.centerIn: parent
                    }
                }
            }
        }
    }

    Popup {
        id: popup
        width: 400
        height: 400
        modal: true
        focus: true
        closePolicy: Popup.CloseOnEscape | Popup.CloseOnPressOutsideParent

        contentItem: ListView {
            id: contentList
            implicitHeight: contentHeight
            implicitWidth: contentWidth
            contentHeight: contentItem.childrenRect.height
            contentWidth: contentItem.childrenRect.width
            orientation: ListView.Horizontal
            interactive: orientation === ListView.Vertical ? contentHeight > height : contentWidth > width
            clip: interactive

            LayoutMirroring.enabled: root.mirrorLayout
            LayoutMirroring.childrenInherit: root.mirrorLayout

            model: 5
            delegate: Rectangle {
                color: "red"
                opacity: (5 - index) / 5
                width: 40
                height: 40

                Text {
                    text: index + 1
                    anchors.centerIn: parent
                }
            }
        }
    }
}

The bug disappears when I comment out the contentWidth line in the ListView, but I do not really understand why