Non English language issue in version2

[Techyuvi]

Hello,
I am using version 2 while using Multi-linguistic feature of Dialogflow, I am facing some issues.
When I am trying to send a Fulfilment Request in Russian Language I am getting "?" instead of actual characters.

{
  "responseId": "9049029d-83a3-4e95-8baf-64cb91deefea",
  "queryResult": {
    "queryText": "?? ??????? ? ???-???? 5 ????",
    "parameters": {
      "from": "??????",
      "to": "???-????",
      "time": "2019-04-12T05:00:00+05:30"
    },
    "allRequiredParamsPresent": true,
    "fulfillmentText": "okk",
    "fulfillmentMessages": [
      {
        "text": {
          "text": [
            "okk"
          ]
        }
      }
    ],
    "intent": {
      "name": "projects/flightquery-82f02/agent/intents/c032518b-f882-4f7f-a49b-fcf57155eeaf",
      "displayName": "bookFlight"
    },
    "intentDetectionConfidence": 1,
    "languageCode": "ru"
  },
  "originalDetectIntentRequest": {
    "payload": {}
  },
  "session": "projects/flightquery-82f02/agent/sessions/559a2540-07d1-fc35-4002-04d179f0b55f"
}

When I am doing the same in version 1, I am getting the Fulfilment request as desired in encoded in russian, in both the cases, I am not defining the charset header. Can we please fix this issue or is there a workaround to fix version 2 of Dialogflow for this issue?

Thanks!

[neerajvashistha]

response received from Dialogflow team,

"Upon checking your Fulfillment settings, you need to remove the "Content-Type: application/json" from the Headers of Webhook."