Directline intermittently not giving responses or giving an echoed response - bots

Question

I have a code that is calling a bot through directline. The directline intermittently stops giving responses or starts giving the same input question as the output. I get only a single messages array and it contains only the same input request message and no response from the bot. I have attached the bot response that I am getting during debugging. Anyone having any clue on this?
using DirectLineConsole;
using DirectLineConsole.Models;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using System.Web;
namespace DirectLineConsole
{
class RequestOrchestrator
{
Conversation objconversation = new Conversation();
public static string secret_key = "BotConnector abc";
public static string Service_URL = "https://directline.botframework.com/api/conversations/";
static void Main(string[] args)
{
RequestOrchestrator objprogram = new RequestOrchestrator();
var task = objprogram.PostMessage("how can i change my phone number?").GetAwaiter().GetResult();
Console.WriteLine("The get static message is " + objprogram.PostMessage("Its 93091").GetAwaiter().GetResult());
Console.ReadKey();
Console.ReadLine();
}
private async Task<bool> PostMessage(string message)
{
bool IsReplyReceived = false;
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("https://directline.botframework.com/api/conversations/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("BotConnector", "abc");
HttpResponseMessage response = await client.GetAsync("/api/tokens/");
if (response.IsSuccessStatusCode)
{
var conversation = new Conversation();
response = await client.PostAsJsonAsync("/api/conversations/", conversation);
if (response.IsSuccessStatusCode)
{
CathyDirectConversation ConversationInfo = response.Content.ReadAsAsync(typeof(CathyDirectConversation)).Result as CathyDirectConversation;
string conversationUrl = ConversationInfo.conversationID + "/messages/";
MessageNew msg = new MessageNew() { text = message };
response = await client.PostAsJsonAsync(conversationUrl, msg);
if (response.IsSuccessStatusCode)
{
response = await client.GetAsync(conversationUrl);
if (response.IsSuccessStatusCode)
{
MessageSetNew BotMessage = response.Content.ReadAsAsync(typeof(MessageSetNew)).Result as MessageSetNew;
foreach (Message responseMessage in BotMessage.messages)
{
Console.WriteLine("The response text " + responseMessage.text);
}
IsReplyReceived = true;
}
}
}
}
return IsReplyReceived;
}