I translated the one on the Reports to Spanish just to find out later than when posting a new thread the phrase was also being using there.
This is a problem of both genre (ie. "abierto" / "abierta"), but also of context (ie. "Discusión abierta", "Mantener abierto")
As usual, I *could* workaround, but that comes in the way of having a perfect translation I would benefit of having one "open" phrase for threads and one for reports.