The canonical URL that is generated is the same one that it generated normally for each page processing, so it uses the options of your menus/modules for that.
For example, if you see component/hikashop and Itemid in the URL, it means that the menu that was selected in the options of your module (the menu 734 in your case) is not a HikaShop listing.
But yes, you might want another URL than the one which is generated. HikaShop just generate the URL based on the settings of the first module/menu which displays a link to the element.
If you need precise URLs, then you'll want to add them manually to your products, with a query, a CSV import, or the interface.