Last line of the menu is not drawn

[dorsamet]

Hi,
I'm creating a menu as follows:

                        PopupMenu menu = PopupMenu(
                            maxColumn: 6,
                            lineColor: Colors.grey,
                            items: repository.getAllUsers().map((e) => MenuItem(
                                title: repository.getUserNameForId(e.id),
                            )).toList(),
                            onClickMenu: (item) {

                            }
                        );
                        menu.show(widgetKey: key);

But the last line is not drawn. Please see attached:

This error occurs when creating all number of column number

Please advise