Hi guys,
First of all, I do not have full admin rights on the JIRA board and have to go through a ticketing system for changes, so that's why the changes I required caused a lot of mess....
It started by a request to change the workflow from: To-Do / In Progress / Done to
To-Do / In Progress / Completed in DEV, UAT / Validated by PO / Validated by Customer (screenshot below)

By doing this, all the issues that were Status = "Done" (350+ issues...) went back to "To-Do" and re-appeared in the backlog (with their number still being strikedthrough)...
So, my questions are the following:
- Is the "Done" Status mandatory in order to close a sprint or is any "green" box alright?
- Is the ability to close a sprint only linked to the columns order in the board setting (need all issues in the last one?)
- Will I every be able to reset all "older sprint stories" to "validated by customer"? At least I know that the issues I want to remove from the backlog have a Resolution = Done
- As a temporary fixe, I tried to set up the following filter to see only the issues that are still REALLY to do in the backlog / current sprint : resolution != done AND ( sprint is not empty OR sprint in openSprints() ), but that doesn't work (even resolution != done alone doesn't work)
Thanks in advance for your help!