This should be relatively simple. You should just have to click "Change Media" , update the URL, click "Apply" and click "Save". Everything seems to work fine up to this point, but when you leave the story map and come back, the old image is still in place. I cannot figure out, why?
This is consistent in three browsers (Explorer, Chrome, and FireFox) and on multiple machines. I have been able to change the text on another story map, but I cannot change the images. I have changed ownership, tried granting different user permissions with no success. Also using different user accounts.
Any help would be greatly appreciated.