//fileserver.lan/Serien /srv/storage/serien cifs defaults,uid=109,gid=116,noauto,x-systemd.automount,x-systemd.requires=network-online.target,user=plex,username=plex,password=plex 0 0

root@plex: systemctl status srv-storage-serien.automount
* srv-storage-serien.automount
   Loaded: loaded (/etc/fstab; generated)
   Active: inactive (dead)
    Where: /srv/storage/serien
     Docs: man:fstab(5)
           man:systemd-fstab-generator(8)

Nov 04 19:49:22 plex systemd[1]: Starting of srv-storage-serien.automount not supported.