I have created 3 categories; Europe (as a parent category) and then I have two sub-categories Croatia and Wales.
In Dashboard > Appearance > Menu I when I only add the category Europe as a menu item, all posts tagged with this category are shown correctly.
However, when I then add the two sub-categories underneath it (to effectively create a drop down) the page Europe will not show any posts.
Why is this happening and is it possible to fix via the admin panel?