Level 4 category URL redirects to Level 3

Question

In some categories of my Magento webshop I have 4 Levels in my menu. The problem is that every Level 4 category menu item is being redirected to the Level 3 Menu item on top. I've already tried empty the core_url_rewrites in the database and reindex, but that doesn't work. It only happens on the 4th level. All other menu-items work fine.

Any ideas how to fix this? Here's the webshop: https://www.hoesjesonline.nl

EDIT: I've tried it with a Level 5 menu-item and then I just get to the Level 5 menu-item. Level 4 still doesn't work.

Answer 1

The problem came from an external Translate URL plugin to translate URL's in cart and checkout. When this plugin is disabled, the categories work fine.