Hello Mia -- Thank you for reporting this issue.
This appears to be a problem only when the story is viewed in Safari as part of a collection (as it is in the link you shared above). There is no issue if you access the story directly using this link: (Farm) Animal Planet.
The maps in that sidecar section are static images, so this is not a problem with map rendering. There appears to be a difference in the way Safari loads and displays images in embedded stories.
We'll look into this more and plan to address it in our next release.
Owen
Owen Evans
Lead Product Engineer | StoryMaps