On The header builder the responsiveness is not automatic as on the legacy menu. You need to adjust the visibility of the elements according to the desired layout on desktop and mobile.
So each BAR, Container, Element on the builder has a customizer tab, on this tab you can hide or show elements according to the screen width.
So you would for example, hide the bar you built for desktop and add a new one for mobile with smaller logo and one of the mobile menus, your you could hide just the elements or containers etc...
Hope it helps