the .basel-products-nav seems to go through products somewhat randomly. In your demo I navigate from a purse to a dress to shoes back to some clothing… Find this very confusing to be honest.
Is there a way to get some sense into this to make it useful?
For example restrict the navigation to the category that’s shown in the breadcrumbs?
Any WordPress theme is a skin for functionality and does not influence or amend its nature and way of working. Please check this on any default theme to get convinced our theme does not cause the problem.
Now, I see. Yes, this navigation shows prev and next product regardless of the category. There is the option to hide it in the Theme Settings > Product page. Related products are products shown in a certain category.