It sounds like a the classic configruation option in the rtpengine when the agents login via internet.
In inventory file there are two parameters: external_hostname and external_port. If external_hostname is passed the installer asumes this OML is going to be cloud and set this file this way:
[root@ip-172-20-1-42 ansible]# cat /etc/rtpengine-config.conf
OPTIONS="-i external/172.20.1.42!YOUR_PUBLIC_IP_HERE -n 127.0.0.1:22222 -m 20000 -M 30000 -L 7 --log-facility=local1"
You must check that the file is this way and you have your public IP inserted.