those are the mount points of my pool:
root@x:/sharedfolders# zfs mount
/sharedfolders/home and sharedfolders/books contents is the same than zfs filesystems mounted on /pool0 (as they should be),
but /sharedfolders/movies contains only 2 empty folders (/sharedfolders/movies/es and /sharedfolders/movies/en)
systemd mount task is this:
root@x:/sharedfolders# systemctl cat sharedfolders-movies.mount
# This configuration file is auto-generated.
Description=Mount shared folder movies to /sharedfolders/movies
So, I suspected that those 2 empty folders they were actual mount points for zfs filesystems, and I tried this:
mount -t zfs -o bind,nofail /pool0/movies/es /sharedfolders/movies/es
And it worked. I was able to see the contents of the zfs filesystem on /pool0/movies/es.
As a workaround, I had created .mount files for all my zfs filesystems that omv is not mounting.