We have 500+ products in multiple categories. When we learned that the Previous/Next arrows navigated the first category for a product we turned off the arrows for the page that contains all the products because the arrows would navigate a seemingly random group.
Now we have updated the products so that the category we want the arrows to navigate, the artist, is always first. The problem is now that we are ready to turn the arrows back on we can't figure out how to do it. A little embarrassing, since we turned it off in the first place!
To turn it on you have to enable the option "Show shortcuts to other category products" in Configuration > Display > Product.
Then you potentially have an override on the view "product / show" which allow to display the previous and next buttons only in some case.
