Exception when sending SMS messages in C# using JamaaTech Smpp .NET client

Question

I have this code in C#:

static async Task Main(string[] args)
{
    var client = new JamaaTech.Smpp.Net.Client.SmppClient();

    JamaaTech.Smpp.Net.Client.SmppConnectionProperties properties = client.Properties;
    properties.SystemID = "...";
    properties.Password = "...";
    properties.Port = 0;
    properties.Host = "...";
    properties.SystemType = "volumen";
    properties.DefaultServiceType = "4433";
    properties.DefaultEncoding = JamaaTech.Smpp.Net.Lib.DataCoding.SMSCDefault;
    properties.AddressTon = JamaaTech.Smpp.Net.Lib.TypeOfNumber.International;
    properties.AddressNpi = JamaaTech.Smpp.Net.Lib.NumberingPlanIndicator.ISDN;
    properties.UseSeparateConnections = false;
    client.AutoReconnectDelay = 30000;
    client.KeepAliveInterval = 15000;

    try
    {
        if (!client.Started)
        {
            client.ForceConnect();
            client.Start();
        }

        var textMessage = new JamaaTech.Smpp.Net.Client.TextMessage()
        {
            DestinationAddress = "...",
            RegisterDeliveryNotification = true,
            SourceAddress = "...",
            Text = "Test"
        };

        client.SendMessage(textMessage);

        client.Shutdown();
        client.Dispose();
    }
    catch (Exception ex)
    {
        client.Shutdown();
        client.Dispose();

        throw ex;
    }
}

I am getting an exception on line client.ForceConnect(); with the following error message

Bind operation failed PDU receive operation timed out

I have tried different configuration variants without success. The SMPP server administrators tell me that I must configure the Bind as a transceiver, which I understand that I am already doing with the configuration of this line

properties.UseSeparateConnections = false;