MonthGrid example not working pop up

[Rusticus]

I tried to use a "MonthGrid" like in the example but I used the whole thing in a pop up. Unfortunately it doesn't work.

Is this a bug or the documentation is wrong or do I something wrong?

Documentation:
https://doc.qt.io/qt-6/qml-qtquick-controls-monthgrid.html

Example:

GridLayout {
    columns: 2

    DayOfWeekRow {
        locale: grid.locale

        Layout.column: 1
        Layout.fillWidth: true
    }

    WeekNumberColumn {
        month: grid.month
        year: grid.year
        locale: grid.locale

        Layout.fillHeight: true
    }

    MonthGrid {
        id: grid
        month: Calendar.December
        year: 2015
        locale: Qt.locale("en_US")

        Layout.fillWidth: true
        Layout.fillHeight: true
    }
}

My usage:

Popup {
                    id: calendar

                    GridLayout {
                        columns: 2
                        
                        DayOfWeekRow {
                            locale: grid.locale

                            Layout.column: 1
                            Layout.fillWidth: true
                        }

                        WeekNumberColumn {
                            month: grid.month
                            year: grid.year
                            locale: grid.locale

                            Layout.fillHeight: true
                        }

                        MonthGrid {
                            id: grid
                            month: endDateVar.getMonth()
                            year: endDateVar.getFullYear()
                            locale: Qt.locale("en_US")

                            Layout.fillWidth: true
                            Layout.fillHeight: true

                            onClicked: (dateEvent) => {
                                console.log( dateEvent )
                            }
                        }
                    }
                }

That's how it looks like: