The capability edit_theme_options still not allowing user to add item to the men

I want to allow a specific user to only be able to edit/add pages and add them to the menu. So I gave him all the capabilities (using the User Role Editor plugin) required to add and edit pages, which works fine.

I also gave him the ‘edit_theme_options’ capability which should allow him to go to Appearance -> Menus and edit the menus. In fact it allows him to go to the section and see the menus and the pages he could add.

However, when the user tries to add a page to the menu structure, it just says it Saved the menu, but the new item doesn’t appear. It seems that wordpress is totally ignoring the changes of this user. From Admin on the other hand this works.

Is there some other permission I need to add to allow the user to add items to the menu?