Why Python print statements does not show up until the application is completed (in C# service)?

Question

I have a little complex code developed using Python 3.8.10 for image processing. This code is interfaced with C# GUI using "Process()" method.

The code is working but the issue is that all my status updates (print statements) in Python do not show up until the end of the code.

For example in python_code.py,

print(f"Loading model {model_name}, please wait......"
......
......
print(f"Inference completed, loading next image, ......")
......
......

C# code is as follows :

public void AI_SJV_run(string ImageFile, RawBGAXrayParameterFiles AI_Recipe)
{
    // https://medium.com/emoney-engineering/running-python-script-from-c-and-working-with-the-results-843e68d230e5
    // https://www.tensorflow.org/hub/tutorials/image_retraining
    MessageEventArgs e = new MessageEventArgs();
    e.message = @"<<<<<<< Script initiaited, please wati.... >>>>>>>";
    ProcessStartInfo start = new ProcessStartInfo();
    Process process = new Process();
    //start.FileName = (Params.Xray_file.DetectionParameters.Algorythm == SJWalgorythm.CONTOUR) ? ContourPython : CirclePython;
    //string pythonFile = string.Format("{0}\\{1}.py", PythonAlgorythmFolder, AI_Recipe.Xray_file.DetectionParameters.PythonAlgorythm);
    string pythonFile = SJV_Inference_code;
    // if (File.Exists(pythonFile))
    start.FileName = pythonEXEPath;
    if (File.Exists(pythonFile))
    {
        if (File.Exists(start.FileName))
        {
            string pythonParams = "";
            // AI_Recipe.Xray_file.DetectionParameters.imageParameters is empty for AI recipe
            string ParameterName = AI_Recipe.Xray_file.DetectionParameters.PythonAlgorythm; 

            pythonParams = pythonParams + string.Format("{0} \"{1}\" ", "--AI_Recipe", ParameterName);

            string arg = String.Format("--ImageFolder \"{0}\" {1}", ImageFile, pythonParams);

            start.Arguments = string.Format("\"{0}\" {1}", pythonFile, arg);

            log.Write("Python file : " + start.FileName + "Python parameters >>> " + start.Arguments);

            m.message = start.Arguments;
            sendPythonMessage(this, m);
            sendPythonMessage(this, e);

            start.UseShellExecute = false;
            start.CreateNoWindow = true;
            start.RedirectStandardOutput = !start.UseShellExecute;
            start.RedirectStandardError = !start.UseShellExecute;

            process.StartInfo = start;

            process.EnableRaisingEvents = true;
            process.OutputDataReceived += SJW_Output;
            process.ErrorDataReceived += SJW_Error;
            process.Exited += new EventHandler(SJW_Exited);

            process.Start();

            process.BeginOutputReadLine();
            process.BeginErrorReadLine();

            process.WaitForExit();
        }
        else
        {
            m.message = "Python executable not found : " + start.FileName;
            sendPythonMessage(this, m);
        }
    }
    else
    {
        m.message = "Algorythm file not found : " + pythonFile;
        sendPythonMessage(this, m);
    }
}
public void AI_SJV_Output(object sender, DataReceivedEventArgs e)
{
    try
    {
        string results = e.Data;
        if (results != null)
        {
            m.message = results;
        }
    }
    catch (Exception ex)
    {
        m.message = "ERROR @ SJW_Output : " + ex.Message + "EXCEMPTION : " + ex.InnerException;
    }
    sendPythonMessage(this, m);
}
private void AI_SJV_Error(object sender, DataReceivedEventArgs e)
{
    string ErrorResult = e.Data;
    if (ErrorResult != null)
    {
        try
        {
            m.message = "SJW Error :" + ErrorResult;
        }
        catch (Exception ex)
        {
            m.message = "ERROR @ SJW_Error : " + ErrorResult + "  " + ex.Message + "EXCEMPTION : " + ex.InnerException;
        }
        sendPythonMessage(this, m);
    }
}
private void AI_SJV_Exited(object sender, EventArgs e)
{
    Bumps bumps = new Bumps();
    try
    {
        m.message = "<<<<<<< Script completed >>>>>>>";
    }
    catch (Exception ex)
    {
        m.message = "ERROR @ SJQ_Exited : " + ex.Message + "EXCEMPTION : " + ex.InnerException;
    }
    sendPythonMessage(this, m);
}

print statements in Python do not trigger "AI_SJV_Output" method until end of the code But at the end, it dumps all statements ran until then.

Any help?