The protocol used to connect to Lightstreamer Server is always the same used to download the Master Push-Page. So if the Master Push-Page is downloaded through HTTP, then HTTP will be used for all the connections to Lightstreamer Server. It the Master Push-Page is downloaded through HTTPS, all the connections to Lightstreamer Server will use HTTPS.

So in order to activate HTTPS connections, you need to download your Master Push-Page through HTTPS.