404 Not Found nginx/1.12.0 Push Notification - php

Question

I'm in big trouble that I have no idea what it can be.
I have an APP that has more than 100k users on the table, I happen to call the GCM service inside LOOP after about 1 minute presents this error message.
I have treated all the fields so as not to be NULL, I do not know what it can be!
Will it be timeout from ajax?
The call in GCM is as follows:
$url = 'https://android.googleapis.com/gcm/send';
$fields = array(
'data' => array(
"mensagem" => $message
),
'registration_ids' => $registatoin_ids
);
if (is_array($data)) {
foreach ($data as $key => $value) {
$fields['data'][$key] = $value;
}
}
$headers = array(
'Authorization: key=' . apiKey,
'Content-Type: application/json'
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
$result = curl_exec($ch);
if ($result === FALSE) {
die('Curl failed: ' . curl_error($ch));
}
curl_close($ch);
Loop to bring the database id-------------
for ($i = 0; $i < $num / 1000; $i++)
{
$query = $con->query("SELECT gcm_regid from registration where status ='S' and LENGTH(gcm_regid) = 152 and app_id=$Id_Aplicativo LIMIT $current_num,1000");
foreach($query as $data)
{
if (!is_null($data["gcm_regid"]))
{
$row[] = is_null($data["gcm_regid"]) ? " " : $data["gcm_regid"];
$cont = $cont + 1;
}
}
// print_r($row);
$pushStatus = send_notification($con, $row, $mensagem, array(
'titulo' => is_null($titulo) ? " " : $titulo, //$titulo,
'sub_mensagem' => is_null($sub_mensagem) ? " " : $sub_mensagem, //$sub_mensagem,
'content_mensagem' => is_null($content_mensagem) ? " " : $content_mensagem, //$content_mensagem,
'content_info' => is_null($content_info) ? " " : $content_info, //$content_info,
'url_imagem' => is_null($path . $nome_imagem) ? " " : $path . $nome_imagem, //$path.$nome_imagem,// Esse Path vem do arquivo Conect.php
'url_audio' => is_null($path_audio . $filenameAudio) ? " " : $path_audio . $filenameAudio, //$path_audio.$filenameAudio, // Esse Path vem do arquivo Conect.php
'tipo_notificacao' => is_null($TipoNotificacao) ? " " : $TipoNotificacao, //$TipoNotificacao
));
$row = null;
$current_num+= 1000;
}
404 Not Found Nginx/1.12.0