Can't authenticate with Hasoffers API using Hasoffers official API call builder

Question

I am using Hasoffers official API call builder

https://developers.tune.com/network/authentication-finduserbycredentials/

This is the call it is giving me (my credentials have been x-ed out)

https://xxxxxxx.api.hasoffers.com/Apiv3/json?NetworkToken=xxxxxxxxxxxxxxxxxxxxxxxxxx&Target=Authentication&Method=findUserByCredentials&email=xxxxxxxxxx%40xxxxxxxxxxxxxxxxx&password=xxxxxxxxw&type=affiliate_user&set_token=1

This is what I am getting back when calling :

{
  "request": {
    "Target": "Authentication",
    "Format": "json",
    "Service": "HasOffers",
    "Version": "2",
    "NetworkToken": "xxxxxxxxxxxxxxx",
    "Method": "findUserByCredentials",
    "email": "xxxxx@xxxxxxxxxx.com",
    "password": "xxxxxxxxxxx",
    "type": "affiliate_user",
    "set_token": "1",
    "_": "1509793486169"
  },
  "response": {
    "status": -1,
    "httpStatus": 200,
    "data": "",
    "errors": [
      {
        "publicMessage": "NetworkToken xxxxxxxxxxxxxx is not authenticated"
      }
    ],
    "errorMessage": "NetworkToken xxxxxxxxxxxxxxxxxxx
 is not authenticated"
  }
}

(I have tested same credentials on tracking board.com that calls affiliate API for same network and it works)