Product Category menu item not working, wrong url!

I am trying to create a simple category menu at the top of my page but only the dummy data categories work, when I create my own product category it doesn’t display the url correctly, missing out the “/product-category/” section.

So I add a product category and add a product to this category. I then create a primary menu to display at the top of my page and select one dummy data product category “Posters” and another custom made products category, so I now have 2 menu items.

Clicking the dummy data “Posters” displays 5 items with the url: https://www.mySite/product-category/posters/

Clicking the custom made prod. cat. just shows an empty page because it is using url: https://www.mySite/customItem/

Does anyone know why this could be happening, and how I can fix it?

Thank you

P.S. Im using woocommerce with the free Artificer theme.