Upload torrent does not "see" content

[koevet]

I have a problem with certain torrent files that I want to seed, and I don't understand what is the problem (I suspect it has to do with encoding).
This is what I do (note that qbittorrent v5.1.0 is running in a docker container on a remote linux box)

• upload the torrent content to the "default save path" folder (e.g. downloads)

• select "Torrent Management Mode": automatic

• leave every other option on the upload modal as default

• create a torrent file

The torrent is uploaded ok but Progress is set to 0% and status: stalled. It looks like qbittorrent does not see the folder that I have uploaded.
Note that this seems to happen mostly when the folder name or content contains characters like à, ß etc.

After a number of times, eventually it works, but it can take many many trials. Any idea what the problem may be?