Input_audio_format not correctly setting (Advanced Voice API)

API
1

Im calling the API to get the ephemeral key here

Doc: https://platform.openai.com/docs/api-reference/realtime-sessions/create

{
  "id": "sess_001",
  "object": "realtime.session",
  "model": "gpt-4o-realtime-preview-2024-12-17",
  "modalities": ["audio", "text"],
  "instructions": "You are a friendly assistant.",
  "voice": "alloy",
  "input_audio_format": "pcm16",
  "output_audio_format": "pcm16",
  "input_audio_transcription": {
      "model": "whisper-1"
  },
  "turn_detection": null,
  "tools": [],
  "tool_choice": "none",
  "temperature": 0.7,
  "max_response_output_tokens": 200,
  "client_secret": {
    "value": "ek_abc123", 
    "expires_at": 1234567890
  }
}

But when I get the 200 status response, this is the object i receive
Full OpenAI Response: {

“id”: “sess_AgIP6X5skqhY9NskTp4hw”,
“object”: “realtime.session”,
“model”: “gpt-4o-realtime-preview-2024-12-17”,
“expires_at”: 0,
“modalities”: [
“text”,
“audio”
],
“instructions”: "You are a friendly assistant. ",
“voice”: “alloy”,
“turn_detection”: {
“type”: “server_vad”,
“threshold”: 0.5,
“prefix_padding_ms”: 300,
“silence_duration_ms”: 200,
“create_response”: true
},
“input_audio_format”: “pcm16”,
“output_audio_format”: “pcm16”,
“input_audio_transcription”: null,
“tool_choice”: “auto”,
“temperature”: 1.1,
“max_response_output_tokens”: “inf”,
“client_secret”: {
“value”: “ek_676490ac32c4819081879947063c028d”,
“expires_at”: 1734643944
},
“tools”:
}

input_audio_transcription is set to null, even though i set it to the parameters the doc says to when calling for the authentication

Has anyone else had this problem? When we get the response back from the ephemeral auth it’s refusing to change from null and therefore I can’t get any of the user generated transcriptions.