Primary menu formatting on iPad sized devices

The primary menu seems to format strangely when viewed on iPad sized devices.

I have three menu options, and the menu displays on iPad sized devices as if it were being viewed as part of the toggle menu. This, however, is not the case as the menu-toggle is disabled at this size/resolution screen.

Are you able to advise/assist with a resolution preferably via CSS if possible? The CSS i’ve tried messes up the toggled menu formatting on other devices (I’m no CSS expert)