If the configuration by default works so the plugin and the moodle server configuration are correct. So there are a few things you may want to check:
First. By chance, are you missing the protocol in the url?
>url setting like this: " 10.0.9.92/bigbluebutton/"
It should be http://10.0.9.92/bigbluebutton/, if that is the url you use to access to your BBB server, which by the way, assuming you have a n standard and complete installation, it should show you the demo page.
Also, if you test this URL in your browser http://10.0.9.92/bigbluebutton/api/ do you get the same XMl you got from the test-install server? You should. If you don't so your BBB server is broken.
And finally, did you replace the salt (AKA shared secret) by default with the one used by your server? The one that comes by default only works for test-install, at least you replace the salt in your BBB server.
By the way, the XML response you got in the browser has nothing to do with the response your Moodle server should get. That only means that your client computer can communicate with the BBB server, but doesn't mean the Moodle server can.