Transcribe is missing conversation not identify speakers

here is audio file which I am using transcribe is not properly identifying speakers in conversation. Its actually mixing it
dl sndup net /zf5r/Conversation.mp3

response = transcribe_client.start_transcription_job(
    TranscriptionJobName=job_name,
    Media={'MediaFileUri': f's3://{bucket_name}/{file_name}'},
    MediaFormat='mp3',
    LanguageCode='en-US',
    OutputBucketName=bucket_name,
    Settings={
        'ShowSpeakerLabels': True,
        'MaxSpeakerLabels': 2
    }
)

if status['TranscriptionJob']['TranscriptionJobStatus'] == 'COMPLETED':
    
    # Load the transcript from S3.
    transcript_key = f"{job_name}.json"
    transcript_obj = s3_client.get_object(Bucket=bucket_name, Key=transcript_key)
    transcript_text = transcript_obj['Body'].read().decode('utf-8')
    transcript_json = json.loads(transcript_text)
    output_text = ""
    current_speaker = None
    
    items = transcript_json['results']['items']
    
    for item in items:
        
        speaker_label = item.get('speaker_label', None)
        content = item['alternatives'][0]['content']
       
        # Start the line with the speaker label:
        if speaker_label is not None and speaker_label != current_speaker:
            current_speaker = speaker_label
            output_text += f"\n{current_speaker}: "
            
        # Add the speech content:
        if item['type'] == 'punctuation':
            output_text = output_text.rstrip()
            
        output_text += f"{content} "
        
    # Save the transcript to a text file
    with open(f'{job_name}.txt', 'w') as f:
        f.write(output_text)

spk_0: Hello, thank you for calling airline customer support. My name is Sarah. How can I assist
spk_1: you today? Hi, Sarah, I need to cancel my flight booking that I made last
spk_0: week. I’m sorry to hear that you need to cancel your booking. May I have your mobile number to pull up your reservation?
spk_1: Sure. It’s 5551234567.
spk_0: Thank you. Could you please verify your full name and the departure date of your flight for security purposes?
spk_1: My name is John Smith and the departure date is February 5th. Thank you,
spk_0: Mr Smith. Ive located your booking. I see that you are eligible for a refund. Would you like to proceed with the cancellation? Yes, please. All your booking has been canceled successfully. The refund will be processed within 24 hours to the original form of payment. Is there anything else I can assist you with today? No,
spk_1: that’s all. Thank you for your help.
spk_0: You’re welcome, Mister Smith. If you have any further questions or need assistance in the future, feel free to reach out to us. Have a great day.