HTTP/2 Server can disconnect a client for several reasons, when server wants inform to client the reason why is disconnecting, it sends a GoAway message to client with information about disconnection.
Use OnHTTP2GoAway event to catch the reason why server has disconnected (if client wants to close a connection, can use the method close to send the reason why is closing the connection).
TsgcHTTP2GoAwayProperty Object contains the information about disconnection