We built a Story Map Series with the side accordion layout. On one page we have an image that with the ability to open in a new window enabled. The main page is a PDF, the image being opened is a jpg both reference by URL. When you click on the small image to open full size, it hides behind the main map content window, as shown below.
This happens only in Internet Explorer versions 10+. (The story map does not work in IE 9 at all.) The story maps works perfectly in safari, firefox and chrome.
The map is hosted and we are not interested in downloading and hosting on our own site.
Full app is here, page in question is the "Stream Buffers".