Job a11n
(@jobthomas)
Automattic Happiness Engineer
Hi @demi28. Storefront has 3 different “locations” for menus. The primary and secondary only display on desktop, and the “handheld” location is the one that displays on mobile.
Creating a new menu that has the items you want on mobile, or just using your main menu on both the primary and the handheld locations will fix this:

Link to image: http://cld.wthms.co/CpOZfo
Job a11n
(@jobthomas)
Automattic Happiness Engineer
We haven’t heard back from you in a while, so I’m going to mark this as resolved – if you have any further questions, you can start a new thread.