Only one packet comes from Xplane 11 data packets to C#

Question

I'm developing an XPlane 11 ground control station in C# .net framework winforms. I am successfully pulling data from XPlane. However, I have a problem. Data comes via UDP. After selecting the data packets that I want to send in the Xplane interface, I start the program and only the packet with the smallest index number is transmitted from the selected packets. If I just pick a random package I can successfully see it in the c# interface. What is the reason of this?

Note: My data retrieval code is communicating with the UAV. So I don't think there is a problem in my code.

Only one packet comes from Xplane 11 data packets to C#

private UdpClient udpClient;        
private IPEndPoint endPoint;
readonly byte[] ExpectedSignature = { 68, 65, 84, 65, 42 }; 
bool IsValidSignature = true;
byte[] receivedData;

public Form8()  
{ 
    InitializeComponent();  
    InitializeUdpClient();  
}

private void InitializeUdpClient()
{   
    udpClient = new UdpClient();  
    endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 49001);  
    udpClient.Client.Bind(endPoint);
}

private void BtnGetData_Click(object sender, EventArgs e)    
{   
    timer1.Start(); 
}

private void Timer1_Tick(object sender, EventArgs e)
{   
    byte[] data = GetData();  
    ShowData(data); 
    ResetData(); 
}

private byte[]  GetData()
{ 
    receivedData = udpClient.Receive(ref endPoint);  
    return receivedData;  
}

private void ResetData()
{   
    receivedData = null;    
}

private void ShowData(byte[] data)
{
    for (int i = 0; i < ExpectedSignature.Length; i++) 
    { 
        if (data[i] != ExpectedSignature[i]) 
        { 
            IsValidSignature = false; 
            break; 
        } 
    }
    if (IsValidSignature) 
    {
        for (int i = 0; i < data.Length; i++) 
        { 
            if (i == (data.Length - 1)) 
            { 
                richTextBox1.AppendText(data[i] + "\n"); 
            } 
            else 
            { 
                richTextBox1.AppendText(data[i] + ", "); 
            } 
        }
        
        switch (data[5])//https://www.x-plane.com/kb/data-set-output-table/
        {

            case 1:
                double realtime_value = BitConverter.ToSingle(data, 9); 
                Lbl_1_RealTime.Text = realtime_value.ToString();
                
                double totaltime_value = BitConverter.ToSingle(data, 13); 
                Lbl_1_TotalTime.Text = totaltime_value.ToString();
                
                double missiontime_value = BitConverter.ToSingle(data, 17); 
                Lbl_1_MissionTime.Text = missiontime_value.ToString();
                
                double timertime_value = BitConverter.ToSingle(data, 21); 
                Lbl_1_TimerTime.Text = timertime_value.ToString();
                
                double zulutime_value = BitConverter.ToSingle(data, 29); 
                Lbl_1_ZuluTime.Text = zulutime_value.ToString();
                
                double localtime_value = BitConverter.ToSingle(data, 33); 
                Lbl_1_LocalTime.Text = localtime_value.ToString();
                
                double hobbstime_value = BitConverter.ToSingle(data, 37); 
                Lbl_1_HobbsTime.Text = hobbstime_value.ToString();
                break;
                
            case 3:
                double VindKias_value = BitConverter.ToSingle(data, 9); 
                Lbl_3_VindKias.Text = VindKias_value.ToString();
                
                double VindKeas_value = BitConverter.ToSingle(data, 13); 
                Lbl_3_VindKeas.Text = VindKeas_value.ToString();
                
                double VtrueKtas_value = BitConverter.ToSingle(data, 17); 
                Lbl_3_VtrueKtas.Text = VtrueKtas_value.ToString();
                
                double VtrueKtgs_value = BitConverter.ToSingle(data, 21); 
                Lbl_3_VtrueKtgs.Text = VtrueKtgs_value.ToString();
                
                double VindMph_value = BitConverter.ToSingle(data, 29); 
                Lbl_3_VindMph.Text = VindMph_value.ToString();
                
                double VtrueMphas_value = BitConverter.ToSingle(data, 33); 
                Lbl_3_VtrueMphas.Text = VtrueMphas_value.ToString();
                
                double VtrueMphgs_value = BitConverter.ToSingle(data, 37); 
                Lbl_3_VtrueMphgs.Text = VtrueMphgs_value.ToString();
                break;
        }
    }
    else 
    { 
        IsValidSignature = true; 
    }
    
}

Answer 1

I solved the problem. Xplane is sending the data packet in one go. That is, after the initial identification bytes, 36 bytes of data are the data of the first index. The next 36-byte index is added to the end of the existing 41-byte packet. Each time an index is selected, the packet extends by 36 bytes. My mistake was that I thought of each index as a 41-byte packet. Thanks to everyone who replied. :)