I have some epics configured, and I see them from Issues and when I click on child Stories (the parent is properly configured).
But in the board I do not have the option to group by Epic.
Also, when I enter in Backlog, in the list there are no epic links displayed. Then, when I click on a story that has an epic, the epic link appears. But still the "Epic" dropdown says that there are no epic in my project.
Before clicking:

After clicking:
