After an unsuccessful attempt to connect the auxiliary port (isc_que_events) any subsequent api call that needs to communicate with the server hangs forever (so the client application hangs forever)

Configure the server (superserver) so that the firewall does not block the main service port (3050) but blocks the specified Aux port (3060 in this case)
--- firebird.conf ---
#RemoteServiceName = gds_db
#RemoteServicePort = 3050
RemoteAuxPort = 3060
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Make a connection to the remote server using tcp/ip then call isc_que_events which will timeout after 10-15 seconds with a isc_network_error (335544721). Now make a call that requires communication with the server (e.g. isc_start_transaction ) and the application (library) will hang forever

Right now I can see that it goes wrong when it tries to send the subsequent packet to the server ( port->send(packet) ) but the debugger didnt go any further into the code from there so unsure excatly where after that it fails.