Speech To Text with REST API returns 'Success' with a partial word

Question

I'm trying to use REST API for Speech To Text as below.

            const endpoint = `https://${azureRegion}.stt.speech.microsoft.com/speech/recognition/conversation/cognitiveservices/v1`;
            const query = new URLSearchParams({ language: 'en-US' });
            const url = `${endpoint}?${query}`;

            const headers = {
              'Ocp-Apim-Subscription-Key': azureSubscriptionKey,
              'Content-Type': 'audio/wav; codecs=audio/pcm; samplerate=16000',
              'Accept': 'application/json'
            };
        
            const response = await fetch(url, {
              method: 'POST',
              body,
              headers,
            });

And I used a wav file tested by many people as a reference, saying "What's the weather like".

API response looks not correct because DisplayText ontains only a partial word of the audio. ("The.")

Recognition result: {
  RecognitionStatus: 'Success',
  Offset: 8900000,
  Duration: 44500000,
  DisplayText: 'The.'
}

FYI the code above gets the arraybuffer of the wav file for 'body'. Please let me know how to fix it it...