Почему приложение логики с Poll-Async никогда не запрашивает конечную точку проверки состояния, даже если конечные точки работают нормально

Question

У меня есть приложение Azure Logic, использующее шаблон poll-async, но конечная точка проверки состояния никогда не вызывается, даже если она работает нормально при вызове из PostMan. Приложение логики в Azure настроено для поддержки асинхронного шаблона, и начальная конечная точка возвращает заголовок расположения с правильным путем для конечной точки проверки состояния.

Вот пример кода

//State dictionary for sample - stores the state of the working thread
    private static Dictionary<int, bool> runningTasks = new Dictionary<int, bool>();
    /// <summary>
    /// This is the method that starts the task running.  It creates a new thread to complete the work on, and returns an ID which can be passed in to check the status of the job.  
    /// In a real world scenario your dictionary may contain the object you want to return when the work is done.
    /// </summary>
    /// <returns>HTTP Response with needed headers</returns>
    [HttpPost]
    [Route("startwork")]
    public async Task<HttpResponseMessage> longrunningtask(int FileId)
    {
        runningTasks[FileId] = false;  //Job isn't done yet
        new Thread(() => ImportFileDataFromLogicAppRequest(FileId)).Start();   //Start the thread of work, but continue on before it completes
        HttpResponseMessage responseMessage = new HttpResponseMessage(HttpStatusCode.Accepted);
        responseMessage.Headers.Add("location", String.Format("{0}://{1}/api/SocialNetworks/Facebook/status/{2}", Request.Scheme, Request.Host, FileId));  //Where the engine will poll to check status
        responseMessage.Headers.Add("retry-after", "20");   //How many seconds it should wait (20 is default if not included)
        return responseMessage;
    }

    /// <summary>
    /// Method to check the status of the job.  This is where the location header redirects to.
    /// </summary>
    /// <param name="id"></param>
    /// <returns></returns>
    [HttpGet]
    [Route("status/{id}")]
    //[Swashbuckle.Swagger.Annotations.SwaggerResponse(HttpStatusCode.BadRequest, "No job exists with the specified id")]
    //[Swashbuckle.Swagger.Annotations.SwaggerResponse(HttpStatusCode.Accepted, "The job is still running")]
    //[Swashbuckle.Swagger.Annotations.SwaggerResponse(HttpStatusCode.OK, "The job has completed")]
    public HttpResponseMessage checkStatus(int id)
    {
        //If the job is complete
        if (runningTasks.ContainsKey(id) && runningTasks[id])
        {
            runningTasks.Remove(id);
            return new HttpResponseMessage(HttpStatusCode.OK)
            { ReasonPhrase = "Some data could be returned here" };
        }
        //If the job is still running
        else if (runningTasks.ContainsKey(id))
        {
            HttpResponseMessage responseMessage = 
                new HttpResponseMessage(HttpStatusCode.Accepted);
            responseMessage.Headers.Add("location", String.Format("{0}://{1}/api/SocialNetworks/Facebook/status/{2}", 
                Request.Scheme, Request.Host, id));  //Where the engine will poll to check status
            responseMessage.Headers.Add("retry-after", "20");
            return responseMessage;
        }
        else
        {
            return new HttpResponseMessage(HttpStatusCode.BadRequest)
            {
                ReasonPhrase = "No job exists with the specified ID"
            };
        }
    }

    /// <summary>
    /// Imports file data from a request comming from a Logic App
    /// </summary>
    /// <param name="FileId"></param>
    /// <returns></returns>
    //[HttpPost]
    //[Route("ImportFileDataFromLogicAppRequest")]
    public async Task ImportFileDataFromLogicAppRequest(int FileId)
    {
        bool stop = false;
        while (!stop)
        {
            await Task.Delay(50000);
        }
        runningTasks[FileId] = true;
    }

в настоящее время метод длительного запуска имеет бесконечный цикл только для целей отладки, хотя даже если это не так, конечная точка проверки состояния никогда не вызывается.