I’m using nzbdrone/sonarr exclusively with torrents, and it seems that once a single episode of a full Season download has been imported, it removes the entire Season before the other episodes can be imported (or more specifically in my case, before they can even be rsync’d to the local server from the seedbox).
Is the intended behavior that nzbdrone will check for the rest of the episodes immediately after it sees the first file, assume something when wrong with the download since those files aren’t available yet, and cleaning up after one successful import?
What method in Sonarr are you using for torrents?
When Sonarr isn’t getting information from the download client to import (Transmission, Deluge or uTorrent), it only uses the available files at import time to determine what to import.
Once it imports all the available files it will check if there are any other files in the folder before deleting it. Since files are being rsync’d down still it may not see them at all and thinking that’s it.
Drone factory and Torrent Blackhole both have this same issue, you’re much better off using a supported download client and a remotely mounted file system to avoid these issues.