Hi,
Since HikaShop 2.5.0, HikaShop doesn't create associated modules for the menu items.
Now, the system forces one virtual module for the categories listing menu items and the options are directly in the menu items.
If your problem is that you have the products displayed directly under the categories, not only when you click on a category, then the problem is not about removing the submodule. It's about changing the "sub element filter" setting to "direct sub elements" in the "products options" tab of your menu item via the Joomla menu manager.