I'm getting the same results. In addition, while I can use AGOL maps on the main stage, they are very slow to load for some reason.
Sorry you are having an issue with your story map. I branched your comment into a new thread since you are having a separate issue as well.
Are you using Map Journal or Map Series? Is the web map slow when you view it in the ArcGIS.com map viewer or just in the story map? How many layers are in the web map and are there a lot of detailed features in any of the layers?
Could you make your story and it's maps/layers public and post (or private message me) the URL so I can take a look?
Retrieving data ...