When viewing a New Story Map with a lot of content (images and videos are embed and maps are from arcgis online) everything seems to work.
But when a user reaches to the end of the story and then scrolls up, or clicks to a specific section of the header menu, the side panel image does not display at the right section.
The problem is solved if you follow this instruction BUG-000108862: When viewing a Story Map Journal through a specific ..
But it is annoying for the story map audience...