[Samba] Samba public IP issue

[cristiant at newro.co]

Hello,
I am running two Samba Domain Controllers on as Ubuntu 18.04 VMs 
installed on two physical hosts. I've managed to bind them and to run 
the replication. My issues is that the private IP address is advertised 
and the replication fails. Even though I update the DNS entry  after a 
few minutes the changes are overwritten and the replication fails again.
Can someone help me with this issue? Is there any option to make this 
changes permanent?
Thank you in advance!

Best regards!