Hi Matt,
Oh, sorry, I thought this issue was in the Cascade Builder, but now I realize you were seeing this issue when checking your story on the My Stories page of the Story Maps website. That sounds like a known beta issue that should be fixed in our next release, which will be available this Thursday morning.
Great story, by the way!! As I was looking through it, I noticed a few of the images were loading a bit slowly. That is also a known beta issue which should be fixed Thursday; however, you'll have to upload your images again to take advantage of the fix. There's no need to re-add all the images, but you should see a big improvement by re-uploading any that are slow.
Owen
Owen Evans
Lead Product Engineer | StoryMaps