DNS Server : SOA question El Capitan Server

Hello,

how can the SOA be set on El Capitan Server DNS ?

The Server is indeed reporting the domain name (example.com) as SOA, but some services (DYNDNS secondary server services) seems to expect the SOA to be the primary server, such as in this case ns1.advedi.com

Currently I have for the primary server a mac mini running the latest version of El capitan Server allowing zone transfer, and as secondary servers a Snow Leopard (Server) 10.6.8 running DNS + one secondary server service from DynDNS.

Both secondary servers report the same issue with the SOA

domain name: example.com

primary server: ns1.example.com (main server, allowing zone transfer)

secondary server: ns2.example.com (taking information from ns1.example.com)

dynDNS servcie (taking information from ns1.example.com)

I do not see on the GUI how to set it up. Do I need to edit the zone?

Thank you