Third level category - and no ideea what to look for

-- url of the page with the problem -- : webdesign.emidee.de/baycicle/hikashop-me...egories-listing.html
-- HikaShop version -- : 4.4.0
-- Joomla version -- : 3.9.24
-- PHP version -- : not necessary
-- Browser(s) name and version -- : not necessary
-- Error-message(debug-mod must be tuned on) -- : none

Hi @all and sorry for asking this, aber English isn´t my native language and I have no idea what exactly I need to take a look for.
here comes my problem: when someone goes on the page, the shop primary should disoplay the manufacturer. <-- check, works fine
When clicking on the selected manufacturer, the list of available profuct categories should be displayed <-- check, works fine
No products should be shown there - or listed with the headings of the categries <-- no check, articles / products are displayed
When clicking on the available product categories, the products of this category should be present <-- no check - all is empty

On the page I inserted 2 e.Bikes and linked them to the manufacturer liv and sorted them unter
root
-Manufacturer 1
--E-Bkes
--Cross % Gravel.....
-- Road
......
-Manufacturer 2
--E-Bkes
---- Bike 1
---- Bike 2
--Cross % Gravel.....
-- Road
......

But when clicking on: Manuf.2, E-Bikes then nothing is visible - only directly in the category tab.

Any hints, how to solve this? Thanks to all of you to be so kind.

Hallo nobody has an answer to this? Please be so kind to support

Would PAY for help!