Joomla 5 Questions for positioning additional Menues

Hello CEd,
I've tried out the accordeon menu but for this I have to rearrange a lot of menue's and the idea to go only deeper on a topic if the intro is of interest is also vanished.
The Topic (as example page 1) "Nachweisgrenzen" of the list himself contains an article. That's the intro to the topic. This can not be selected, it just act as open/close button. In my concept the + (see example 2) hast to be clicked to open the sub level. Also the selected article is not highlighted in the menu after clicking on him. 
The marking of an selected article (See 3) on long lists is important for me. Maybe I do something wrong.
Cheers, Helmer

1)  borgmann-aquaponik-hydroponik.ch/j53c/in...grenzen-de/aluminium
2)  borgmann-aquaponik-hydroponik.ch/j53k/in...grenzen-de/aluminium
3)  borgmann-aquaponik-hydroponik.ch/j53k/in...brokkoli-microgreens  

ok I see, you must enable the option
"Enable link redirect on parent item" >> YES
this will redirect the link and only open/close with the icon