Hi,
There are two possibilities:
- the product isn't linked to any category. Since the backend products listing bases itself on the currently selected category in the left side explorer, it won't display the product on the listing in that case.
- similarly, if the product is linked to a category outside the tree of the currently selected category, you won't see it. For example: the default category is "product category". If you previously created a category sister to that category and directly linked to the "root" category and then linked that product to the sister category, then you won't see it if you search for it while the "product category" is selected in the explorer.
So first, I would recommend to click on the "check database" button of the configuration page of HikaShop.
Among other things, it will check for any products without a category and link them to your main category.
Also, when you search, first click on the "root" category on the left explorer to make sure it searches among all the categories.