Hierarchy does not work when "Group by releases" is used.

[Rashmi Ratnani]

Hi 

We are using a roadmap with this kind of a view set up where I am grouping the list by Releases. Grouping by releases | Advanced Roadmaps for Jira Data Center and Server 3.29 | Atlassian Documentation

Currently, only the epics are attached to a release, not individual stories under the epics.

However, in this group by view, the Hierarchy does not work.

Even if I select the Hierarchy as Epic to Sub-task, the epics do not show as expandable. Please see the screenshot attached.

Any ideas, why this doesn't seem to be working?

Thank you. 

/RR