RemovedAfterSprintStart() does not work if you omit the sprint name

[Lee Cash]

Hello,

The documentation regarding this function states: 

removedAfterSprintStart(board name, [sprint name])

Displays issues that have been removed from the named sprint (or all active sprints if second argument is not provided), after the sprint has started.

However, if I leave the second argument blank (so it focuses on the current sprint) this function does NOT return any task I have removed from the sprint after the sprint has started. 

Interesting, its sister function addedAfterSprintStart DOES work as advertised. Am I missing something here? I don't want to have to update my dashboard every time I start a new sprint; I want this function to work with whatever sprint is currently active without manual intervention. 

Thanks in advance, 

Lee