Epic Burndown report does not display the chart depending on how the Epic Link was created.

Issue Summary

Epic Burndown report does not display the chart depending on how the Epic Link was created.

Steps to Reproduce

The Epic Burndown report does not display the chart when using sequence 1 and 2 below to create the Epic Link:

Sequence 1:

• New Scrum Project Area
• Create button, new issue Epic; Epic Name 1, unassigned, SCRUM7-1
• Create button, new issue Story 1, Assigned to "user1", Epic link to "Epic Name 1 - (SCRUM7-1)"
• Create button, new issue Story 2, Assigned to "user1", Epic link to "Epic Name 1 - (SCRUM7-1)"
• Open Epic Burndown report: It shows:

  This chart cannot be displayed
  There are no estimated issues in this epic.
  Estimate issues in the Backlog
  

• Click the button "Estimate issues in the Backlog"
• Click each story and assign an Estimative at the quick edit: Story 1, Estimate 5 pts; Story 2, Estimate 3pts;
• Open Epic Burndown report: same results.

Sequence 2

• New Scrum Project Area
• Create button, new issue Epic; Epic Name 1, unassigned, SCRUM8-1
• Open backlog, Epic panel and expand the Epic information
• Use the link "Create an issue in Epic" to create a new issue
• Create Story 1, Assigned to "user1"
• Create Story 2, Assigned to "user1"
• Open Epic Burndown report: It shows

  This chart cannot be displayed
  There are no estimated issues in this epic.
  Estimate issues in the Backlog
  

• Click the "Estimate issues in the Backlog"
• Click each story and assign an Estimative, like Story 1, Estimate 5 pts
• Open Epic Burndown report: same results.

Sequence 3

• New Scrum Project Area
• Create button, new issue Epic; Epic Name 1, unassigned, SCRUM9-1
• Create Story 1
• Create Story 2
• Edit Story 1 created, search for the field "Epic Link"
• At the Epic link field - type "SCRUM9..." - It will show the "Epic Name 1 - (SCRUM9-1)" at the suggestions - Select it and confirm
• Edit Story 2 created, search for the field "Epic Link"
• At the Epic link field - type "SCRUM9..." - It will show the "Epic Name 1 - (SCRUM9-1)" at the suggestions - Select it and confirm
• Open the backlog
• Click each story and assign an Estimative, like Story 1, Estimate 5 pts; Story 2, Estimate 3pts;
• Open Epic Burndown report: it will show correctly the graph, as expected.

Expected Results

The graph is presented for all three sequences of steps.

Actual Results

The graph is not presented for sequence 1 and 2:

This chart cannot be displayed
There are no estimated issues in this epic.
Estimate issues in the Backlog

The team can not keep track of the work that was done or to be done at the Epic.

Workaround

Currently, there is no known workaround to fix the already incorrect Epic/Issues.

The overall recommendation is to create the issue first, and then, edit the issue adding the Epic Link.

Note: Issue was not reproduced using Jira 7.13.8