It’s important to have seperate directories for unfinished torrent downloads and complete ones, and only have sonarr pick up from the completed one

Back when I used Torrents instead of Usenet for sonarr, I had only the one folder, since Plex would generally pick up the library changes automatically anyway. I’d assume that Jellyfin is similar, although I don’t use it enough to know for sure. These days I use only Usenet for sonarr/radarr since I’m paying for Usenet and it’s excellent for automation/new content, and SABnzbd provides both incomplete and complete folders by default anyway.