products are showed on a category list ?

-- url of the page with the problem -- : www.zebra-design.be/index.php/shop
-- HikaShop version -- : HikaShop Starter 2.6.3 [1605112330]
-- Joomla version -- : 3.5.1
-- PHP version -- : 7.0
-- Browser(s) name and version -- : google chrome 51.0.2704.84 m

Dear,

on the page www.zebra-design.be/index.php/shop I get 4 categories which I want but also underneath products which I don't want with template tz_interiart_v_1.1.

Hi,

It's just like you configured your shop and the listing, no one else to "blame".

Go edit the menu item for the categories listing in question. Under the tab "Product option" in the box "Data display" you have probably set the option "Sub elements filter" to "All sub elements", meaning it will display products from all the (sub) categories in the category listing.
Set it to "Direct sub elements" instead. Accordingly, it will then only list products that are in the category shown.

Of course, you need to also make sure that your products are only in the "most sub" category, not in any parent categories.

Yes that was the problem, unbelievable easy to fix but apparently not easy to find ...
I've spend some hours to this but one thing is sure I will not forget this

Thank you very much

Regards,
sindb

A bit of a long read, but worthwhile as it explains not only few examples but also all options: the documentation on "Content display on the frontend" .

-> Menu options display -> Data display -> Sub elements filter, where it states:

(...) For products, you choose to only display products in the current category or in all the sub categories of the current category regardless of their depth.