I’ve always used Transmission, since there’s a Docker container I use that bakes in your VPN-of-choice & a killswitch.

https://haugene.github.io/docker-transmission-openvpn/

That said, it looks like it hasn’t been updated in over a year… I wonder if there’s anything else out there that does the same thing as this. (EDIT: Yes. Google brings up plenty of choices.)

Your -arrs see the torrent download folder as /mnt/arr-stack/torrents/completed, and qBittorrent sees it as /downloads.

Maybe this is only a problem with Transmission, but I’ve had trouble making my Arr stack play nice with torrents when the different apps think downloads live in different folders.