https://doc.zentyal.org/en/directory.htmlafter documentation:
Know Limitations
Your hostname can not match your NETBIOS name, the NETBIOS name is generated using the left part of the domain, for example, if your hostname is ‘zentyal’ your domain can not be ‘zentyal.lan’, but it could be ‘zentyal-domain.lan’
what 'netbios name' is it about? domain or host???
and how about smb.conf:
workgroup = ?? is it netbios domain name or something else?
netbios name = ?? again what name it is domain or host?
there is also picture where host name and netbios name is the same - 'zentyal'