Roots Discourse

Foundation mechanisms stop working as soon as I start the dev server


I am currently developing my first Sage Theme and I have the problem, that as soon as I start the dev server with yarn start some data attributes and classes stop working but work again as soon as I stop the dev server. E.g. the sticky attribute in my header navigation <div data-sticky data-margin-top="0" data-sticky-on="small"> or classes in the WP Navigation 'menu_class' => 'vertical medium-horizontal dropdown menu']) !!} They are not applied, or better, only sometimes. If I often reload enough they are back and applied sometimes.

What can be the reason, and how can I solve this? Any help appreciated.

Many thanks,