Twitter Kit RestAPI does not support IPv6? - Rejected from Apple

My app is rejected due to not supporting IPv6 network support.

Here is message from Apple:

We discovered one or more bugs in your app when reviewed on iPhone running iOS 11 on Wi-Fi connected to an IPv6 network.

Submitting a Tweet through the app does not post it on the feed or on the Twitter web-site.

My app is very simple and posts text using RestAPI call. Here is code snippet.

let client = TWTRAPIClient(userID: userid)
let url = "https://api.twitter.com/1.1/statuses/update.json";
let message:[String:Any] = ["status": text]
var error: NSError?
let request = client.urlRequest(withMethod: "POST", url: url, parameters: message, error: &error)

DispatchQueue.main.async {
  client.sendTwitterRequest(request) { (response, data, ConnectionError) -> Void in
    if let error = connectionError {
      print("Error: \(error.localizedDescription)")

      DispatchQueue.main.async {
        completion(error)
      }
    } else {
      DispatchQueue.main.async {
        completion(nil)
      }
    }
  }
}

Did anyone experience this?

Removing AFNetworking from Podfile fixed the issue