Always print the last message read with zigbee in C#

See more:

C#

Arduino

communication

Hi,
I'm using an Arduino with a Zigbee to send data from sensors and a Raspberry Pi with an another Zigbee to read the data which is 10 bytes with a head and a stop.
I'm on Windows 10 IoT and I code with VS 2019.
My issue is that my RPI read the data but is getting more and more late so I'm not in real time anymore.
I know that the problem comes from the buffer that force me to read each message and I'm willing to change that.
I would like to read only the last message in the buffer but I don't know how to.
Thank you for your help,
Romain.

<pre>private async Task<ZigBeeCommResult> Read()
        {
            var retvalue = new ZigBeeCommResult();
            try
            {
                
                _dataReader = new DataReader(_zbCoordinator.InputStream);
                
                var numBytesRecvd = await _dataReader.LoadAsync(10);
                byte[] data = new byte[10];
                retvalue.TextResult = "";
                Debug.WriteLine(_dataReader.UnconsumedBufferLength);
                while (_dataReader.UnconsumedBufferLength > 0)
                {
                    for (uint j = 0; j < 10; j++)
                    {
                        data[j] = _dataReader.ReadByte();
                        //Debug.WriteLine(data[j]);
                        retvalue.TextResult += data[j];

                    }
                }
                txtHeader.Text = retvalue.TextResult;


            }
            catch (Exception ex)
            {
                retvalue.IsSuccessful = false;
                retvalue.TextResult = ex.Message;
            }
            finally
            {
                if (_dataReader != null)
                {
                    _dataReader.DetachStream();
                    _dataReader = null;
                }
            }
            return retvalue;
        }

and

public void DispatcherTimerReaderSetup()
        {
            // configure dispatcher
            _dispatcherTimerReader = new DispatcherTimer();
            _dispatcherTimerReader.Tick += DispatcherTimerReader_Tick;
            _dispatcherTimerReader.Interval = new TimeSpan(0, 0, 0, 0, 500);
            _dispatcherTimerReader.Start();
        }

        public void DispatcherTimerReader_Tick(object sender, object e)
        {

            Read();
            
        }

What I have tried:

I tried to read faster than I send data but error and I also searched how to empty the buffer but I didn't find.