When I click on the “Our work” menu item, the entire blog/gallery opens in one page or tab, with all categories visible. The list of categories that should appear under the main menu item is not shown.
Yes, I added the categories through Appearance>Menus. I tried using an actual page (instead of a custom link), but that doesn’t work, either. In both cases, only the main menu item (“Our work”) is visible, and clicking on it loads the entire blog/gallery.