[Samba] check_account: Failed to convert SID to a UID

[Sabolowitsch, Stefan]

Hi there,
get this error message when accessing a share.
# check_account: Failed to find local account with UID 663 for SID S-1-5-21-3855358086-4131983242-2739128174-31637 (dom_user

I have a SLES 15 SP3 with this Samba Config.
[global]
        workgroup = TEST
        realm = TEST.LOCAL
        security = ADS
        preferred master = no
        encrypt passwords = yes
        log level = 0
        log file = /var/log/samba/%m
        max log size = 100
        max open files = 8000
        winbind enum users = Yes
        winbind enum groups = Yes
        winbind use default domain = Yes
        winbind nested groups = Yes
        idmap uid = 600-20000
        idmap gid = 600-20000
        template homedir = /home/%D/%U
        usershare allow guests = No
        winbind refresh tickets = yes
        template shell = /bin/bash
        load printers = no
        printing = bsd
        printcap name = /dev/null
        disable spoolss = yes
        username map = /etc/samba/mapfile

        client min protocol = SMB2
        client max protocol = SMB3

[inb]
        comment = Inbetriebnahme
        path = /u1/inb
        valid users = "@TEST.LOCAL\Domain Users"
        write list = "@TEST.LOCAL\FS_SWLIEF_inb_RWXD", "@TEST.LOCAL\Domain Admins", "@TEST.LOCAL\hydadm"
        force group = "mpdv inb"
        writeable = yes
        #read only = yes
        force create mode = 0777
        create mask = 0777
        directory mask = 0777
        force directory mode = 0777
        access based share enum = yes
        hide unreadable = yes

/etc/nsswitch.conf:
passwd: compat winbind
group: compat winbind

a "getent group / user" works correctly even a "wbinfo -i testuser" without error.
At first sight everything seems OK.

Does anyone have any idea what this could be ?
# check_account: Failed to find local account with UID 663 for SID S-1-5-21-3855358086-4131983242-2739128174-31637 (dom_user


Thanks for any help
Stefan Sabolowitsch