[Samba] After upgrade samba 4.16 -> 4.18, unable to access cifs-shares exported from a netapp-server

[thom_schu at gmx.de]

Hallo,
yesterday we made an upgrade from samba 4.16 to 4.18 (ubuntu 22.04 + sernet).
After the upgrade, all CIFS-Shares exported from our NetApp couldn't be accessed anymore neither from windows
nor from linux.

The NetApp-Server reported the following errors:

secd.netlogon.noServers: None of the Netlogon servers configured for Vserver (svm) are currently accessible via the network
secd.ldap.noServers: None of the LDAP servers configured for Vserver (svm) are currently accessible via the network
secd.lsa.noServers: None of the LSA servers configured for Vserver (svm) are currently accessible via the network

It's like the NetApp-server were not able anymore to connect to the samba4-server

Because the CIFS-shares are essential, we had to act fast and went back to samba 4.16 from the backup.
Then everything worked fine again.

Is there any change in samba 4.17 or 4.18 that can cause this behave ?
I read the changelog, but couldn't find anything (with my minimal understanding)

regards

TH