When you ask if the NAS is mounted... in the Promox GUI? I'm not sure where it says mounted, but under the Summary it's Enabled, but not Active.
At the mount command I get:
mount
/dev/mapper/pve-root on / type ext4 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)...