Push error 102 on android

Hi all,

I’m trying to send push notifications to android and iphone.
I have 2 site from where i send them from. Both have the same piece of code for sending them.
But on 1 site they fail and i get a 102 error as failure reason in the android area (see code). If i send a notifications through the ionic push testing they all succed.

Message ID of error: 24ebd76ab54811e59e32f2bfcbd4ee03

I send them with PHP/Symfony/Guzzle

Code for sending notifications:

foreach($aDevices as $aDevice)
  $aUserIds[] = $aDevice->getUserId();
$aData = array('android' => array('title' => 'Nieuwe kandidatuur', 'alert' => 'Kijk snel!'), 'ios' => array('title' => 'Kijk snel', 'alert' => 'Nieuwe kandidatuur'));
$oGuzzle = new GuzzleHttp\Client();
$oResponse = $oGuzzle->post(sfConfig::get('app_Ionic_push_link'), [
  'auth'    => [sfConfig::get('app_Ionic_push_username')],
  'headers' => ['Content-Type' => 'application/json' , 'X-Ionic-Application-Id' => sfConfig::get('app_Ionic_application_id')],
  'json'    => ['tokens' => $aUserIds, 'notification' => $aData, 'production' => true]

If you need more info, tell me!