Почему curl возвращает 1 хотя параметр CURLOPT_RETURNTRANSFER установлен

this is the servers array that I keep top level domain names and extensions

 protected $servers = array(
        
        "com.tr" => "whois.nic.tr",
        "gen.tr" => "whois.nic.tr",
        "web.tr" => "whois.nic.tr",
        "k12.tr" => "whois.nic.tr",
        "org.tr" => "whois.nic.tr"
    );

I am required to get whois info so I wrote this function


    function whois($domain,$ext)
    {
               $server=$this->servers[$ext];
               $domain=$domain.".".$ext;
             
        if (function_exists('curl_version')) {
            $curl = curl_init();
            curl_setopt($curl, CURLOPT_URL, $server);
            curl_setopt($curl, CURLOPT_PORT, 43);
            curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($curl, CURLOPT_TIMEOUT, 5);
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $domain."\r\n");
            $result = curl_exec($curl);
            curl_close($curl);

                    
                    echo print_r($result);
                   
        } else {
            trigger_error('cURL is not found!');
            exit();
        }




    }

I  am using this way
whois("google","com");

This function works  for google.com and It gives me the correct domain information But when I execute  for google.org.tr then (this is the intersting part)  sometimes retuns 

    
    No match found for "google.org.tr"(whis is expected)
 
     and  somethimes return "1"