RetryQuery not working after throttling

Hi everyone,

We are using the recommended approach for throttling. 

Here is the method we are using to execute the requests:

 public void ExecuteQueryWithRetry(ClientContext ctx, int retryCount, int backOffInterval, ILog LOG)
        {
            DateTime startTimeStamp = DateTime.Now;
            try
            {
                int retryAttempts = 0;
                int retryAfterInterval = 0;
                bool retry = false;
                ClientRequestWrapper wrapper = null;
                LOG.Debug($"Client Context: {ctx.GetHashCode()}");
                LOG.Debug($"Throttled : {Throttled}");

                if (Throttled)
                {
                    while (Throttled)
                    {
                        LOG.Debug("Still throttled...");
                        Thread.Sleep(100);
                    }
                    Thread.Sleep(new Random().Next(500));
                    LOG.Debug("Throttled finished");
                }

                while (retryAttempts < retryCount)
                {
                    try
                    {
                        if (retry && wrapper != null && wrapper.Value != null)
                        {
                            LOG.Debug("Execute request with wrapper value...");
                            ctx.RetryQuery(wrapper.Value);
                            LOG.Debug("Execute request with wrapper value finished");
                            Throttled = false;
                            return;
                        }
                        else
                        {
                            LOG.Debug("Execute request...");
                            ctx.ExecuteQuery();
                            LOG.Debug("Execute request finished");
                            Throttled = false;
                            return;
                        }
                    }
                    catch (WebException ex)
                    {
                        var response = ex.Response as HttpWebResponse;
                        // Check for throttling
                        if (response != null && (response.StatusCode == (HttpStatusCode)429 || response.StatusCode == (HttpStatusCode)503))
                        {
                            Throttled = true;
                            wrapper = (ClientRequestWrapper)ex.Data["ClientRequest"];
                            retry = true;
                            string retryAfterHeader = response.GetResponseHeader("Retry-After");
                            if (!string.IsNullOrEmpty(retryAfterHeader))
                            {
                                if (!Int32.TryParse(retryAfterHeader, out retryAfterInterval))
                                {
                                    retryAfterInterval = backOffInterval;
                                }
                            }
                            else
                            {
                                retryAfterInterval = backOffInterval;
                            }
                            LOG.Warn($"We got throttled! Will back off for {retryAfterInterval} seconds.");
                        }
                        else
                        {
                            LOG.Debug(ex.StackTrace);
                            throw;
                        }
                    }
                    Thread.Sleep(retryAfterInterval * 1000);
                    retryAttempts++;
                }
                throw new MaximumRetryAttemptedException($"Maximum retry attempts '{retryCount}' has been attempted.");
            }
            finally
            {
                if (LOG.IsDebugEnabled)
                {
                    TimeSpan duration = DateTime.Now - startTimeStamp;
                    LOG.Debug($"Executed CSOM query in [{duration.TotalMilliseconds.ToString("0.00")}] ms");
                }
            }
        }

We got the 429 error and after that we wait the recommended time until we execute again the request.

The request is re-executed using the RetryQuery method. After the method is called, we got no error but the request is not executed.

Do you have any ideas why we encounter this problem?