Splunk API works on Postman but not on PHP

I have a CakePHP application where I’m calling https://hkrtrainings.com/splunk-api to make a search and obtain its results. It works as a charm when I try it on Postman, but when run by my server it doesn’t return results every time. In fact, when I call the API constantly inside a while loop, it does tend to bring results, although sometimes it could take more 2 minutes to return something.

I’m calling Splunk this way:

$querying = array( “search” => “search index=api_sandbox OR index=api_prod token=” .$token, “output_mode” => “raw” ); $querying = http_build_query($data); try{ $curl = curl_init();

        curl_setopt_array($curl, array(
        CURLOPT_URL => 'https://mysplunk:8089/servicesNS/user/environment/search/jobs/export?' . $querying,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_ENCODING => '',
        CURLOPT_MAXREDIRS => 10,
        CURLOPT_TIMEOUT => 0,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_SSL_VERIFYPEER, false,
        CURLOPT_USERPWD => 'Basic ' . base64_encode("user:password"),
        CURLOPT_HTTPHEADER => array(
            'Authorization: Basic ' . base64_encode("user:password")
          ),
        CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
        CURLOPT_CUSTOMREQUEST => 'GET',
        ));

        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);

        $response = curl_exec($curl);


        curl_close($curl);

        return $response;
    }catch (\Throwable $th) {
        Log::error("callApi ERR: " . $th->getMessage());
        debug("Error: " . $th->getMessage());
        return false;
    }

The API call is run inside a CakePHP Shell Task, and for the record when executed the Shell Task through console command (php bin/cake.php Queue.Queue runworker) the API does return results without empty results.

Why this strange behavior could be occurring?