cifs/SMB automountd not working when moved from 24.04 as on 22.04

I have a fresh installation of Ubuntu 24.04.1 on an new SSD.

I would like to take over as much as possible from my old system 22.04, especially the configuration of my automounter, but I can't get it to run on the new system. No matter what I do, I always get log errors. I have managed a manual mount without .credentials file.

What I have done:

I copied the existing .mount and .automount files from the old to the new system. For example:

-rwxr-xr-x 1 ben ben 320 Sep 27  2023 mnt-synology-Bilder.mount*[Unit]Description=Mount for //192.168.0.10/BilderRequires=mnt-synology-Bilder.automountAfter=mnt-synology-Bilder.automount[Mount]What=//192.168.0.10/BilderWhere=/mnt/synology/BilderOptions=credentials=/home/ben/.credentials,rw,vers=3.1.1,_netdev,uid=1000,gid=1000Type=cifs[Install]WantedBy=multi-user.target-rwxr-xr-x 1 ben ben 149 Sep 27  2023 mnt-synology-Bilder.automount*[Unit]Description=Automount for //192.168.0.10/Bilder[Automount]Where=/mnt/synology/BilderTimeoutIdleSec=1[Install]WantedBy=remote-fs.target-r--r----- 1 ben ben 51 Nov 24 23:26 /home/ben/.credentialsusername=Benpassword=p!assword!domain=workgroup

Created a folder to mount:

$ ll /mnt/synology/insgesamt 0drwxr-xr-x 1 root root 30 Nov 24 22:28 ./drwxr-xr-x 1 root root 88 Nov 24 21:09 ../drwxr-xr-x 2 root root  0 Nov 24 23:46 Bilder/drwxr-xr-x 1 root root  0 Nov 24 22:28 testmount/

Nothing has changed at the NAS (old installation can still do the automount), but when I try to perform the automount on the 24.04 PC, this happens:

    $ sudo systemctl daemon-reload    $ sudo systemctl restart mnt-synology-Bilder.automount       $ ll /mnt/synology/Bilder/    ls: cannot access '/mnt/synology/Bilder/': No such device    $ sudo ls -l /mnt/synology/Bilder/    ls: cannot access '/mnt/synology/Bilder/': No such device    $ sudo dmesg    [  896.726231] CIFS: Attempting to mount //192.168.0.10/Bilder    [  896.747517] CIFS: Status code returned 0xc000006d STATUS_LOGON_FAILURE    [  896.747529] CIFS: VFS: \\192.168.0.10 Send error in SessSetup = -13    [  896.747542] CIFS: VFS: cifs_mount failed w/return code = -13    [ 1094.948382] workqueue: delayed_fput hogged CPU for >10000us 8 times, consider switching to WQ_UNBOUND    [ 1143.127709] CIFS: enabling forceuid mount option implicitly because uid= option is specified    [ 1143.127712] CIFS: enabling forcegid mount option implicitly because gid= option is specified    [ 1143.127714] CIFS: Attempting to mount //192.168.0.10/Bilder    [ 1143.154125] CIFS: Status code returned 0xc000006d STATUS_LOGON_FAILURE

It seems pretty sure it's the cifs-mount itself, not the automountd mechanism. If I change the mounts to NFS, they will work. But then they are no longer secure due to the lack of Kerberos.

I really have no idea what I could be doing wrong, because I didn't really change anything, just copied some files.

I have not created an entry for the mountpoint in /etc/fstab. Why should I?

I've been trying for over 2 hours with ChatGPT (and before that alone for just as long). I tried a thousand things, but nothing worked. The “AI” said it was because of the ! in the password, which was never a problem with 22.04 or before, but the solution approaches. Escaping with \ or with single or double quotation marks did not help and neither did a completely different special character.