CNC and template. How can REPRESENTATION be related to LOGIC?

Question

1C-Bitrix

Hello.

Please tell me who understands this unknown little animal (Bitrix). CNC does not work in the catalog, infoblock and component settings do not help. I contacted the TP, which eventually answered the following:

Hello!
I have created a test section on your site that uses the standard templates for the site and catalog component (.default): https://***.ru/testbx/
This section is hidden from visitors, except for administrators, and you can delete it when it is will no longer be needed.
In this section, both category pages and product pages are correctly opened when generating a URL using symbolic codes.
Please contact the site template developer (it is located in the /bitrix/templates/***/ folder), which is used for the main product catalog, in order to understand the nuances of the desired settings in its template.

Unfortunately, this cannot be blamed on the template developer. they don't work with him anymore.
How?! That's how the template can be connected with the work of the CNC ?!) It doesn't quite fit in my head. Or is it an incompetent TP? I checked both options $APPLICATION->IncludeComponent (the one that the TP created and the existing one) - everything is letter for letter. In the admin panel, I did not find any template settings for the section of the created TP. On FTP, the template structure is completely different and there are several templates for the directory section, which one is involved is not clear. Tell me which way to dig? Is it really the template? How to find out which template file is used for a section?