Details sidebar missing * for required fields

When using a Details Sidebar element, the * is not displaying

Set up a Details Sidebar element and check the option "Mark group as required if it contains required fields.". This functionality doesn't work.

The reason for this is the Javascript that takes care of this is using the class that the module assigns to details elements. So the easiest workaround is to simply set the class "field-group-details" to the element.