Hi Lea -- Sorry the Cascade builder is giving you trouble. Sounds like you are encountering a bug we've noticed in map configuration related to duplication of views. Sometimes if you have configured several views with the same map, duplicate one of those views, and then configure the new view the configuration of the previously configured views can be lost.
To workaround this issue, avoid configuring a duplicate view after you have already configured the map in other views; instead, add the map to one view, duplicate that view as many times as you need, then configure the map in all the duplicated views. Alternatively, you can avoid duplicating altogether and just add a new view then manually add the same map as the view's background media.
We plan to address this issue in the next release in September.
Owen Evans
Lead Product Engineer | StoryMaps