Group chat connection error

I have 2 servers both running their own version of openfire and transverse chat client.
I can login to both openfire servers on either server and chat back and forth.
I created a groupchat and cannot get them to join each other if logged into seperate openfire servers.

so 2 domains each have openfire. I can log into either openfire server on eithe domain so there is not a port or connection issue. The issue only presents itself when trying to connect to the groupchat?

any help? I can clear this up a some if this is not understood.