Laravel 5 API using json and Guzzle - laravel

Question

I'm quite new to Laravel 5 but I'm working on project involing 2 servers (S1 and S2). Each one is running a Laravel 5 REST WebService (API) WS1 and WS2.
The workflow is the following :
WS1 : just get a query like http://s1.ip/api/object/1 where 1 is the id of the object. It just "reroute" the query to WS2.
WS2 : get the same kind of query http://s2.ip/api/object/1 using a personnal access token from Laravel/Passport.
WS2 : Ask the local mysql DB to know if the object with id 1 is 'valid' or not.
WS2 : Create a response to the WS1 Query using json. Something like :
{"id": "2", "valid": true}
WS1 : get the response from WS2 and from it create its own response to the initial GET query.
I test my REST API using Postman.
WS2 is work well when using Postman.
But when I try to query WS1, I never get the json from the response that is send from WS2.
Hope I clear.
Here are some of my source code:
routes\api.php
Route::get('/object/{obj_id?}', 'ObjectController#check')->where('obj_id', '[0-9]+');
app\Http\Controllers\ObjectController.php
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use GuzzleHttp\Exception\GuzzleException;
use GuzzleHttp\Client;
use App\Http\Requests;
use App\Http\Controllers\Controller;
class ObjectController extends Controller
{
public function check($obj_id)
{
$token = 'my personnal access tokens from WS2 Laravel/Passport'
$client = new Client();
$body = $client->request('GET','http://S2.ip/api/object/' . $object_id, [
'Accept' => 'application/json',
'Content-Type' => 'application/json',
'Authorization' => 'bearer ' . $token,
])->getBody();
$contents = (string) $body;
$data = json_decode($contents);
dd($data); // to see what's inside $data
The dd($data) output the following : null
I have try many things but I never manager to get the json.
What am I doing wrong. I would really appreciate some help on this.
Thanks
Edit:
Here is the S2 answer I got from PostMan or Rested:
S2 returns the following when using Postman:
Response - http://s2.ip/api/object/1
200 OK
Headers
Date: Thu, 12 Jan 2017 08:38:31 GMT
Vary: Authorization
Server: Apache/2.4.17 (Win32) OpenSSL/1.0.2d PHP/5.6.21
X-Powered-By: PHP/5.6.21
X-RateLimit-Remaining: 59
Content-Type: application/json
Cache-Control: no-cache
X-RateLimit-Limit: 60
Connection: Keep-Alive
Keep-Alive: timeout=5, max=100
Content-Length: 46
Response body
{
"id": "1",
"authorized": false
}