1. Entering to your webstore [Back Office] and [Login].

2. Go to Left [Menu] -> [Catalog] -> [Products].

3. Click [Product] you would like to edit and.

4. Click Tab 4 - [Associations].

4.1. Click [Expand All] in [Associated Categories].

4.2. Select [Home] and [Category] related to your product. (Multiple or cross category is allow)

4.3. Select [Actual Category] in [Default Category]. (Required)

4.4 Click [Save and Stay] to save action above and stay same page.