I’m just using boilerplate Foundation 6 responsive menu markup as demonstrated. https://foundation.zurb.com/sites/docs/top-bar.html#advanced-layout
Running yarn start– in development, no matter the screen size, the primary nav is hidden and the toggle button is always shown even though data-responsive-toggle="responsive-menu" data-hide-for="medium" is specified.
Running yarn build– for production, the menu behaves correctly.
In development, there are no errors in the console other than missing main.css – which is a webpack thing.
I also tried deleting the contents of the .cache loader