before my present machine, I was using a Raspberry Pi 3B, with Raspbian Lite.
to begin with, this was Jessie, later upgraded to Stretch.
when downloading files with Deluge, the torrent-files were placed in a special folder, being watched by Deluge.
once detected and handled, these torrent-files were deleted, as they should be.
now, I an running Debian 9 Stretch and doing exactly the same thing.
everything works well, with one exception:
the torrent-files are not deleted from the watched folder correctly.
they are made hidden and the filename-extension is changed to torrent.invalid, instead of being deleted.
what could be causing this ??