Update dashboard JSON supported in Grafana 5.0.1?

We currently have Grafana Cloud and are running on 5.0.1. For rapid iteration on existing dashboards, sometimes it’s faster to edit the json directly and simply update existing json. It seems as though in v5 the JSON has become read-only, as saving a dashboard ignores any changes made in the JSON view of the dashboard.

Am I missing something?

Thank you.