After installing qBittorrent, I set a directory from which to automatically load .torrent files.
However, as it loaded the files from this directory, it deleted them.
I found a directory
I'm only a newbie, so take my suggestions with a grain ...
1) I have found that double-clicking on a .torrent will recall the original download title.
That may or may not correspond to your queue, so you might want to clear that first.
2) Tools | Options | Downloads
Make sure "Delete .torrent files afterwards" is NOT checked.
Also, I added manual paths for "Defaults"
Copy .torrent files to: C:\torrents\_active
Copy .torrent files for finished downloads to: C:\torrents\_completed
Not complicated, even if not intuitive, but I have avoided re-downloading much by doing comparisons between the results of that.