Unfortunately I do not know enough about Ares to answer your question, sorry. I have never tried the program personally. I suspect the aresmod I tried might be a little different, not sure but was not interested at the time in the chat options it had. And I have uninstalled it since.

I would have imagined a setting 'somewhere' would have incorporated the chat rooms/servers you are registered at or that are enabled. If the setting is not stored in appdata then there might be a chance it's within the program folder. Though programs these days would not normally do that. If it's a server, then perhaps the setting is stored somewhere within the system's settings. It would be pure testing to enable some and disable others to see how it is listed in your settings file(s).

Has your problem worked ever?

There's no option to right-click the room and choose activate or somewhere in the program's menu options?