Hi,
If you don't see the products but they are there, it means that they are not associated to any category or that they are associated to a category which doesn't exist or something like that.
There is no reason an update of HikaShop would generate such behavior.
Please look at the hikashop_product_category table in your database where you can find the association between products and categories. There, search for the id of a missing product and see if you find any association. If you do, please check the corresponding categories in the hikashop_category table.
Based on what you find we should be able to tell you what to do.