Suppose you search in Google for the keyword by category, then we are often displayed fairly well in the organic.
When I do this for a subcategory, the page is usually not found. I think a problem with duplicated content. In the main page you can choose a subcategory through a checkbox.
This yields a URL with a parameter, at the same time there is a canonical to the main category.
But the page with parameter,? Cat=339 is the same as that of the subcategory name.
Example
category: https://www.tenkateshop.com/schuberth.html has no reference to /schuberth/systeemhelmen.html, but does have a reference to https: //www.tenkateshop.com/schuberth.html?cat=339 with as canonical to /schuberth.html.
https://www.tenkateshop.com/schuberth/systemhelmen.html is exactly the same page as https://www.tenkateshop.com/schuberth.html?cat=339, the canonical should have been here https://www.tenkateshop.com/schuberth/systeemhelmen.html.
For keyword schuberth systeemhelmen, the tenkateshop.com ranks with the general schuberth.html page in place 10. But you expect the schuberth systeemhelmen page in that place or even slightly higher. This page can't be found.
Nothing wrong with the /schuberth/systeemhelmen.html page.
This example applies to all categories with underlying pages.
