When I change the default download dir to anything other than /data/incomplete, torrents will not start downloading - in the default folder they start and download fine. The files are created in the new default directory but the download does not start. I tried changing the default in flood, rutorrent, and rtorrent.rc, and the docker mappings.
Edit (solution):
rtorrent (mmap) does not work with mergerfs w/ direct_io enabled
see: https://github.com/trapexit/mergerfs/issues/463