In the setting window under “Server Hostname/IP Address:” if you running more then one hostname to your server and you change it in the settings the server stops working, atleast where you create new channels. Is it tied to the hostname you enter during the installation or is it something that can be edited in some file ?
This setting should be the fully qualified domain name used to access OSP. If you are using a HAProxy in front of all of your OSP-Core servers, it should be the domain that is accessed by users. This relates the to setting in the installer in that the entry you put in is used for the XMPP Chat domain, which should match your OSP Access domain (the one you use for the cores). If your ejabberd server is a separate system, you can set the FQDN for that system that in config.py.