Stateless samples with latest package does not work.

Stateless samples generate json with reference data after upgrade to the latest package. Anyone know how to sort this out?

var answerRequest = this.RequestBuilder.Communications.Calls[callId].Answer(
            callbackUri: "https://xxxxxxxxxxxx/api/callback",
            mediaConfig: new ServiceHostedMediaConfig { PreFetchMedia = preFetchMediaList},
            acceptedModalities: new List<Modality> { Modality.Audio }).Request();
  await GraphApiClient.SendAsync(answerRequest, RequestType.Create, tenantId, scenarioId).ConfigureAwait(false);

Expected Request

{
    "@odata.type": "#microsoft.graph.callAnswerRequestBody",
    "callbackUri": "https://xxxxxxxxxxxx/api/callback",
    "mediaConfig": {
      "@odata.type": "#microsoft.graph.serviceHostedMediaConfig",
      "preFetchMedia": []
    },
    "acceptedModalities": [
      "audio"
    ]
  }

Actual Request

  {
    "$id": "1",
    "callbackUri": "https://xxxxxxxxxxxxxx/api/callback",
    "mediaConfig": {
      "preFetchMedia": {
        "$id": "1",
        "$values": []
      },
      "@odata.type": "microsoft.graph.serviceHostedMediaConfig"
    },
    "acceptedModalities": {
      "$id": "2",
      "$values": [
        "Audio"
      ]
    },
    "participantCapacity": null
  }

Start with the stateless samples that build the Answer request and trace the serialization producing the shown actual JSON. Compare it with the expected request, then verify that the generated payload uses the expected OData type values and arrays rather than reference metadata.