Steps to reproduce

1. Create an Epic;
2. Associate an issue to this Epic and create a subtask under this issue;
3. Create a board filtering for this Epic Link, like this:

   "Epic Link" = Test
   

4. Once the board is created, create a new sprint and start it;
5. Open the board's work tab and check that the subtasks are not appearing;

Current behaviour

Filtering for Epics hide the subtasks in the Work mode.

Expected behaviour

Show the subtasks normally when the board's filter is based on an Epic.