From a desktop (>1024px screens), you will see the normal dropdown menu. In this menu, visitor is normally using a mouse pointer-device, and sub-menu items will expand on mouse-hover. Therefore, both parent (category) pages and child pages can easily be clicked:
However, with small screens (<1024px), the mobile menu will display. The mobile menu builds a tree-structure, where child pages will display on click of the parent (category) item. This obviously mean that "click" on the parent item is reserved to TOGGLE display of child pages, and thus will not actually load the page that is clicked:
This is logical behavior, since small devices don't have mouse, and there is no mouse-HOVER event to display child pages. One could argue that the visitor has no need to load-and-view "category" pages anyway, since their objective is to get to an end-page with the content they are looking for. Also, it's normally bad practice to have images inside BOTH category pages and child-pages of the category, and this is often confusing for the visitor. Furthermore, it would be considered bad practice to load the parent page when it is clicked, while the visitor is simply opening the child-menu items.
Anyway, this is simply a logical limitation of the mobile slidemenu: Click on "category-pages" that contain child-pages, is reserved for toggling display of child-pages.
- If you really want the visitor to visit the parent category-page before they view the child-pages, you could disable the child-pages for a specific category from displaying in the mobile menu. Page settings -> Menu -> "Hide child pages from mobile menu". This means that the visitor will be able to visit the "category" page in the menu, and from within the category page, they will be able to visit child-pages.
- The above procedure is also useful if your category has a large quantity of child-pages. Instead of displaying the child-pages in the menu, you can force the visitor to click the category-page first, where they will see all child-pages listed directly in the page instead.