Invisible "Ghost" Product Categories

Hello all,
I’m currently having an issue with viewing a few of the product categories on our shop page. I have added, edited, and refined our product categories, but there are a few that just aren’t showing up at all.
I’ve edited our shop page to contain all of the category ID numbers, and then arranged them on the Products->Categories list to be in the order that we want.

The missing/ghost categories seem to be in the second position on both the first and second row.

The permalink for the category is working, and visible, but it just will not show up on our main shop page.

Link to main shop page: https://www.spycentre.com/shop-products/
Link to missing shop category: https://www.spycentre.com/product-category/gps-tracking/

Any help would be very much appreciated. Thank you.