Which torrent client are you using? Have you set up labels so that Sonarr/Radarr knows which files it owns? I use Deluge with the labels plugin. I have one called sonarr and in sonarr I set the "category" field on the Download Client settings to sonarr.
Then, not sure if this part is needed, I have Sonarr set to Rename Episodes in the Media Management section.
There is the !selfhosted@lemmy.world community which may be able to help as well.