No pull-down sub-menu

[com2]

Version 8.x-4.1tested on the demo site. According to "External Documentation" pull-down subs should be possible by setting "Show expanded" (in the parent item I guess). Not mentioned in the documentation, I think you also need to set the appropriate "Number of levels to display" in the menu's block setting, where I have set "2". I then added one sub-menu in the demo under the already present "Home". It appears as a permanently visible unordered list item under the parent "Home".

Something must be wrong here or it is simply a matter of missing more detailed documentation.