I’m not a guru with it, I’m a newbie like you but at least I have your setup working.
Take a look at Server/Server Settings/HTTP Binding. In my servers I have http binding enabled on ports 7070 and 7443, if you’re planning to have anonymous users you might take a look at the Registration&Login section as well. In Security Settings I have also moved ClientConnectionSecurity to Optional in order to let it pass the auth part. In this condition I have an html page with Converse.js and I’m able to login on it. I’m now focusing on autologin with prebind (see my latest post), I’m not a guru but I did this well.