I think I have recreated what you saw.
Working with a board for a Company Managed project, on the Backlog screen I have the panes on the left open to display the list of Versions and list of Epics.
I have assigned a Version from the list to the Fix Version field of one of the Epics.
When I click on that Version in the Versions list, all the Epics in the Epics list show opaque/non-selectable.
However, if I assign the Version to the Fix Version field of an issue that is a child of that Epic, then the Epic becomes selectable.
So, through experimentation I see that Versions is used to filter the issues in the Backlog list, not the Epics in the Epics Pane. The Epics pane can be used to apply an additional filter to the issues that have already been filtered by the Versions pane selection.
Hello Atlassian's, This post will be a useful and valuable starter guide for new joiners into the team: https://community.atlassian.com/t5/Jira-Cloud-Admins/Atlympics-Jira-Cloud-New-joiner-st...
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