The log messages that you’re describing sound like your Openfire server is trying to create a server-to-server connection to another XMPP server, but it cannot find the hostname for the XMPP domain name of that server. I’m not sure if there’s more for me to tell you, without understanding more of the setup that you have.
I’m not familiar with xmpphp or livehelperchat. I do not know how they are a part of this.
Good morning, I wish you are well, I want to thank you for your answer to my question, it helped me a lot and I was able to solve the problem. Thank you.