Dashboards rendering wider than viewport in browser/portal

an issue I've been experiencing since the introduction of adaptive dashboards. I make relatively narrow min width dashboards that have elements anchor to both ends so it stretches to the width of the viewport.. but since adaptive dashboards the width of the dashboards are always rendering wider than the viewport. 

For example I have a dashboard thats 1150 full width but when generated in a viewport more than 1150 (in this case 1280ish) it will generate blank space to the right and always have a scrollbar at the bottom.. is this bug of this adaptive feature or am I misusing it?