The limitation is really on the Server process, which should close after 3.5 hours, after which you can start a new instance.
Please send us to support@lightstreamer.com the log for a check (or did you mean that you had no log produced?).

If you observe the scenario from a client or from a Remote Adapter, then you should see the sockets closing;
but, actually, we cannot exclude that some actor in the middle keeps the sockets open; in that case, the socket will just become mute.