TM4C129ENCZAD: Telnet Failing to Connect

I have a number of custom boards that are running a modified version of the dk-tm4c129x enet_uip example. All of these custom boards are connected to a 48 port ethernet switch and are controlled via a computer running a c# program. Occasionally a board will fail to connect to the computer via telnet,

public TelnetConnection(string Hostname, int Port, ref bool result)
        {
            try
            {
                tcpSocket = new TcpClient();
                tcpSocket.ReceiveTimeout = 1000;
                tcpSocket.SendTimeout = 1000;
                tcpSocket.NoDelay = true;
                IPAddress card = IPAddress.Parse(Hostname);
                tcpSocket.Connect(card, Port);
                result = true;
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"TelnetConnection Error: {ex.Message}");
                result = false;
            }
        }

In the C# program I try to connect multiple times, but the TIVA MCU will not respond. Below is a Wire Shark output,

I am able to identify the board that is failing, but don't know how to preserve its current state to examine what is happening with a jtag debugger.

Does anyone have any suggestions on how to debug or fix this issue?

Thanks,

Allan