[JIRAALIGN-2318] Epics Grid: Filtering by Release  ≠ Unassigned Backlog doesn't work

Issue Summary

Epics Grid: Filtering by Release  ≠ Unassigned Backlog doesn't work

Steps to Reproduce

1. Login
2. Go to the Epics grid.
3. Filter it by Release  ≠ Unassigned Backlog.
4. Check the Epics list.

Expected Results

Only Epics that are assigned to the Release appear.

Actual Results

Epics that are in the Unassigned Backlog appear as well.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available