The Full Width Banner is a Feast Layout that allows adding a call-to-action below the menu, on all posts and pages, to promote things like an ebook, cookbook or courses.
This is site-wide and can not be manually turned off on individual pages or posts.
Note: this is different from the Top Banner available in Feast+.
Mobile only
You can add the feast-mobile-only class to elements that you only want to display on mobile, and not on desktop.
Desktop only
You can add the feast-desktop-only class to elements that you only want to display on desktop, and not on mobile.
Clear your cache
After creating the Full Width Banner Feast Layout and assigning it, make sure to clear your cache.