Thanks for reaching out and thanks for using the Cobalt theme with BoldGrid Post and Page Builder for WordPress!
I tried adding a Wishlist item and was unable to. Whenever I went to open the Wishlist link no item would populate. Is that the issue you were speaking of or was it a totally different issue altogether?
In regards to your Main Menu, you should vist the Menu section of your WordPress dashboard and create a custom menu link for the Wishlist URL if you would like to display it in your header menu. Be sure to save your menu updates after you finish your edits.
I recommend reaching out to WishList directly for any plugin related issues. I’m not sure how good there support is but they should be able to offer some guidance on how to setup your WishList items.
I hope this helps. Please let us know if you have any other questions.