This is kind of a confusing question so I'll do my best:
When under Plans -> Program board, and assigning Features to sprints, there is an oddity with due dates.
If the Feature has no sprint set in it's sprint field, and you drag and drop the Feature card into a sprint lane on the board, it auto-changes the due date to the last day of that sprint. Ok fine so far.
If you manually set a sprint in a Feature, say sprint 1 with a due day of April 1, and then drag the card to sprint 2 with a due date of May 1, it does NOT update the due date field of the Feature. It keeps the due date April 1 even though you assigned it sprint 2 with a due date of May 1.
Why does the system work that way? It's causing confusing because now the sprint end date and the due date of the Feature are no longer in sync.