Sorry, Guust – i was not clear in my earlier message.
I can select one or as many as I want, but i have selected all of them as categories (attaching screenshot) in Appearence>Menus.
I meant to say that i have not added individual custom links with category URLs, but used the CPT categories ‘widgets’ to add them to the menu.
As i have about 100 categories and will be adding listings regularly (and even users will add listings) , so it will be difficult to manually keep track which categories are populated at any time or not. To start with maybe only half the cateogories may have a listing, so there will be many empty categories- hence i wanted to ‘hide’ these in the menu, and then they show automatically when the first listing is published.
thanks, Vivek