Custom post type & custom taxonomy prev/next links

Hello All!

I can’t seem to find a solution for this. I have created a custom post type and custom taxonomy ( using Custom Post type UI ) and now I need to add navigation Next/Previous post,but while staying in the same taxonomy.

This doesn’t work:
next_post_link(‘%link’, ‘Next’, TRUE, ”, ‘vertical’);

This does:
next_post_link(‘%link’, ‘Next’);

So it seems like setting the the post navigation to stay within the same taxonomy ( vertical ) does not work.

Any ideas?

Could it be the way the CPT was setup or the taxonomy was created?