How to use "Keep incomplete torrents in"?

[Simone000]

I want to use a temporary folder and move only completed downloads into another folder,
I think the option is by using "Keep incomplete torrents in".

in my case:
volumes:
- ./config:/config
- /mnt/datawork/download:/downloads
- /mnt/datawork/qbittorrenttmp:/qbittorrenttmp

with configuration:
Default Save Path: /downloads
Keep incomplete torrents in: /qbittorrenttmp

however new torrents will just go into error status,
also docker exec qbittorrent-nox vi /config/qBittorrent/data/logs/qbittorrent.log
doesnt say much

btw using subpath does seems to work:
Keep incomplete torrents in: /downloads/temp will work

But I would like to add the folder to Plex so I rather be an entire different path, is it possible?

Thanks

p.s.
in the meantime I found a workaround using .plexignore file with content: temp/
but a complete different path would be appreciated if possible