Agile Board Velocity Report incorrect after changing a workflow scheme

There is an issue with 'Velocity Report' on our agile scrum boards. The issue comes about after switching a workflow; original workflow had a 'Closed' status as the final status & in the new workflow there is not a 'Closed' Status.

When you switch the workflow you are prompted to map the existing status of 'Closed' to the new status of 'Resolved'. Conversion was successful. The updated issue still has the correct resolved date and sprint field still has the correct sprint name selected. On the old sprint reports, the issue will be removed from the sprint and the Velocity Report no longer shows the issues story points as completed.

Workaround
The work around is to make sure to not move the old Status from being mapped to a column:

If you remove the old Status from a mapped column it will disappear and the reports will no longer be correct. If you leave the old status with the warning icon the reports will continue to load as expected.

Example:
https://answers.atlassian.com/questions/181492/completed-velocity-has-disappeared-from-velocity-charts-after-workflow-change