Here are a few examples of the problematic StoryMaps:
https://storymaps.arcgis.com/stories/6b77f8b881844a5dab07f676e909ab30
https://storymaps.arcgis.com/stories/91b4ee32f57a459d99b61b70b653ccaa
The problem is when using iPhone's Safari browser to open these StoryMaps, and turn on the Translation in the Safari, then the StoryMap will crash.
I noticed the problematic StoryMaps are all using Map Tours whereas the ones that are using Slide Bar had no problem! For example this one works seamlessly after switching on Translation in Safari.
https://storymaps.arcgis.com/stories/94433894050845af8c597427eb6339a0
PS: All of them work well on desktop web browser, this issue only happens on mobile devices.
maybe a bug that you can report as product enhancement by opening up a ticket with ESRI tech support.
Thanks!