— Your HOST/ is the default but HOST/NAMESPACE is the one you want.
— You have to create an io object every time you want to join a different namespace i think
— Quoting the docs:
A new Socket instance is returned for the namespace specified by the pathname in the URL, defaulting to /. For example, if the url is http://localhost/users, a transport connection will be established to http://localhost and a Socket.IO connection will be established to /users.