Hi,
You have the "Remove products and categories id in URLs" setting activated in the HikaShop configuration.
So in that case the id of the product is not included in the URL of the product details page.
The alias (like "kasza-kuskus-perlowy-1-kg") is taken from the "alias" option of the product if specified, or generated from the "product name" of the product. As you have the "Unicode Aliases" setting deactivated in the Joomla configuration, only a-z and 0-9 characters are allowed for the alias. So if you have other characters in the product name, they will be stripped when generating the URL of the product details page on the listings.
Then, when you click on the link on the listing, in order to know which product to load, the routing system can only base itself on the alias of the URL so, for example: "kasza-kuskus-perlowy-1-kg". It will try to search for a product with that alias, and if no product is found, it will try to look for a product with that name (replacing the - with spaces).
So the reason why it work for some products and not others is because some products don't have special characters in their name while others do.
So there are several solutions to your issue:
- activate the "Unicode Aliases" setting of the Joomla configuration to allow for special characters in the URLs
- turn off the "Remove products and categories id in URLs" setting to keep the id of the products in the URLs (and thus, regardless of the alias in the URL, the system will find the product based on the id)
- enter an alias without special characters in the products