i was gonna publish after i find the solution for last thing to be added but tysm 
one extra thing is if you want to unmount/mount in dolphin instead of just automount
this solution will help BUT its little bit clunky so you either live with “harmless error“ or remove automount
Start these steps after completing basic setup step 8.
Step 1: Update fstab Options
sudo nano /etc/fstab
Change your entry to includeusers andip=:
//hostname.local/sharename /mnt/nasname cifs users,credentials=/etc/smbcredentials_nasname,ip=192.168.x.x,uid=1000,gid=1000,iocharset=utf8,vers=3.0,_netdev,nofail,x-systemd.automount 0 0
Step 2: Fix Credentials Permissions
sudo chown root:yourusername /etc/smbcredentials_nasname
sudo chmod 640 /etc/smbcredentials_nasname
if you want to add multiple NASs :
sudo chown root:yourusername /etc/smbcredentials*
sudo chmod 640 /etc/smbcredentials*
Step 3: Apply Changes
sudo umount -l /mnt/nasname
sudo systemctl daemon-reload
sudo mount -a
Step 4: If NAS Disappears from Dolphin Sidebar
sudo systemctl start mnt-nasname.automount
now it should be mounted but if you want to unmount →wait a sec → click again on unmount now its unmounted
and after mounting , you may see:
An error occurred while accessing 'HA', the system responded: mount error(16): Device or resource busy
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs) and kernel log messages (dmesg)
This is harmless — share is already mounted.
Withx-systemd.automount, Dolphin unmount works like this:
-
First unmount → share unmounts but automount watcher stays active
-
Clicking folder → immediately remounts
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Second unmount → fully stops automount watcher