ArcGIS StoryMaps embedded in an ArcGIS Hub site with a custom domain refuses to connect when both ArcGIS Hub and ArcGIS StoryMaps are shared to the organization.

Workaround

Add an image to the ArcGIS Hub site with an image hyperlink to ArcGIS StoryMaps:

1. In ArcGIS Hub, click Customize > Layout > Image.
2. After adding the image, expand Options. 
3. Under Image Hyperlink, select Open: Same Tab and add the image hyperlink.

Steps to Reproduce