" Nothing in firewall is blocking connections between this two servers when it comes to powerdns.
I've attached both pdns confs from master/slave, maybe that can help.
Thanks @Peter On master server, every domain is set to MASTER, and on slave is set to SLAVE.
Before you make our nameservers the primary (master) set in your Premium DNS account, you'll need to contact support for your system and your DNS server software to configure your own nameservers as the secondary (slave) set.
You must set your DNS slave nameservers to initiate AXFR requests from both of our master zone transfer servers (not to be confused with secondary servers).
Used to automate administration of secondary servers.
When you create a new primary zone on one server (master server), all slave servers (the "Super Slaves" list) will be notified that there is now a new zone available.