spring-cloud-netflix: Zuul post retry on 503

We have a service that returns 503 responses when some dependencies are not available. We are observing that in this situation zuul retry one time.

The problem is that the request is a POST with json body and the first time the body is correctly sent, but when zuul retries, the body is sent empty and it results in a bad request to the client. We are in Angel.SR3 but the response is the same with SR6

{
  "result": {
    "code": 400,
    "info": "Bad Request"
  },
  "errors": [
    {
      "code": "requestBodyInvalid",
      "description": "request body is invalid"
    }
  ]
}

Any idea of how to retry with body?? it seems a serius bug to me

Thanks in advance!!