Are you using using a Boxed layout for your site instead of Fullwidth? If so, then yes, this is an unfortunate side effect of the unique layout of Icon. With fixed elements, browsers calculate their position relative to the viewport. Because Icon has a unique fixed sidebar, we add some padding to the page to offset the content correctly. If you select a Fixed Top navigation with a boxed layout on Icon, the effect you’re describing will take place.

You can still use the Fullwidth layout with a Fixed Top navbar, and everything works as expected in all other stacks. This is one unfortunate “quirk” as you called it that we can do nothing about due to the nature of how browsers handle these elements.

Let us know if this answered your question satisfactorily. If not, please don’t hesitate to let us know so that we can continue to look into the matter for you.

Thanks!