azure speech recognition crash the console-app on linux IOT

hi there,
i have a console app that uses azure for speech recognition offline from microphone (by KeywordRecognitionModel table) on linux IOT(raspberry pi).

when i run it, at first time it works correctly and can recognize my word, but after 3 or more recognition , it crashes the app, even try-catch cant handle it.

Note : the following code works good on windows PC, without any crash or error, but on linux raspberry pi it crashes the app.

using Microsoft.CognitiveServices.Speech;
using Microsoft.CognitiveServices.Speech.Audio;
using System;
using System.Diagnostics;
using System.Runtime;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;

namespace VoiceAssistant
{
    class Program
    {

        static async Task Main()
        {
        bool working = false;
            while (true)
            {
                try
                {
                    if (!working)
                    {
                        Console.WriteLine("**true working**");

                        working = true;
                        await PropertyStart();
                    }

                }
                catch (Exception ex)
                {
                    Console.WriteLine("**false working**");

                    working = false;
                    Console.WriteLine(ex.Message);

                    Console.ReadLine();

                }
            }

        }

        private static async Task PropertyStart()
        {
            int count = 0;

            Console.WriteLine("Start 2");
            try
            {
                //var config = SpeechTranslationConfig.FromSubscription("key", "westus");

                Console.WriteLine("Step 1");


                //RecordingPanel recordingPanel = new RecordingPanel();

                var keywordModel = KeywordRecognitionModel.FromFile("my_home.table");

                Console.WriteLine("Step 2");



                var audioConfig = AudioConfig.FromDefaultMicrophoneInput();

                var keywordRecognizer = new KeywordRecognizer(audioConfig);
                //keywordRecognizer.Properties.SetProperty("SPEECH-ObjectCountWarnThreshold", "10000");

                Console.WriteLine("Step 3");




                while (true)
                {


                    try
                    {

                        Console.WriteLine("Start Result");



                        KeywordRecognitionResult result = await keywordRecognizer.RecognizeOnceAsync(keywordModel);


                        Console.WriteLine("A Start Result");

                        // Checks result.
                        if (result.Reason == ResultReason.RecognizedKeyword)
                        {
                            count++;

                            Console.WriteLine("Stop");

                            //await keywordRecognizer.StopRecognitionAsync();

                            //await keywordRecognizer.StopRecognitionAsync();
                            Console.WriteLine("a Stop" + result.Duration.TotalSeconds.ToString());


                            Console.WriteLine(count.ToString() + $"We recognized: {result.Text}");
                            //recordingPanel.StartBtn_Click();
                            //keywordRecognizer.Dispose();


                        }
                        else if (result.Reason == ResultReason.NoMatch)
                        {
                            Console.WriteLine($"NOMATCH: Speech could not be recognized.");
                        }
                        else if (result.Reason == ResultReason.Canceled)
                        {
                            var cancellation = CancellationDetails.FromResult(result);
                            Console.WriteLine($"CANCELED: Reason={cancellation.Reason}");

                            if (cancellation.Reason == CancellationReason.Error)
                            {
                                Console.WriteLine($"CANCELED: ErrorCode={cancellation.ErrorCode}");
                                Console.WriteLine($"CANCELED: ErrorDetails={cancellation.ErrorDetails}");
                                Console.WriteLine($"CANCELED: Did you update the subscription info?");
                            }
                        }
                        //await RecognizeSpeechAsync();
                        Console.WriteLine("**");
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine("Error in :::: " + ex.Message);
                    }

                }

            }
            catch (Exception ex)
            {

                Console.WriteLine("Error " + ex.Message);

            }
            Console.ReadLine();
        }



}