I don't think there is any change in the API. My suspension is that after a recent upgrade to this server they either have a bug that they no longer sending an expected SUCCESS response, or it's taking too long to send it, and b then #AndStatus retries to b send it again, and I end up with dozens of the same replies until I realize it and delete it from the #AndStatus outbox. But that's a lot of assumptions on my part. I don't get the multiple replies using the web client or Mustard for Android. (Mustard is super old and hasn't been updated in like a decade, it still OStatus/GNUSOCIAL as StatusNet). #AndStatus doesn't have the same failure when I post a new quip, nor does it when replying to a post using my friendica account that I have set up as GNUsocial/Ostatus.