Symfonium reports it’s playback to the server, the server should do the scrobbling in that case if it does not then it’s a bug on it’s side.
At the same time Symfonium broadcast the necessary information locally so that if you have last.fm or other compatible scrobbling app it can scrobble too.
There’s no real gain to have internal scrobbling inside the app since there’s dedicated apps for that that works and the servers can do it too.