Problems with async & sync

[SergPavlov89]

Hi, we use this code for logging email delivery.

class Kafka extends Component
{


    public $url;

    public function logger($topic, $value){

        //$logger = new Logger('my_logger');
        //$logger->pushHandler(new StdoutHandler());
        $config = \Kafka\ProducerConfig::getInstance();
        //$config->setMetadataRefreshIntervalMs(10000);
        $config->setMetadataBrokerList($this->url);
        //$config->setBrokerVersion('1.0.0');
        //$config->setRequiredAck(1);
        $config->setIsAsyn(false);
        //$config->setProduceInterval(500);
        $producer = new \Kafka\Producer(
            function() use ($topic, $value)  {
                return [
                    [
                        'topic' => $topic,
                        'value' => $value,
                    ],
                ];
            }
        );
       // $producer->setLogger($logger);
       /* $producer->success(function($result) {
            var_dump($result);
        });
        $producer->error(function($errorCode) {
           // var_dump($errorCode);
        });*/
        $producer->send(true);

    ...
$resp = \Yii::$app->kafka->logger('sendMails', json_encode($kafka));

We had some troubles when using sync requests after pushing first msg our producer cyclically sends and "ddos" our consumer. Only restart help.
When we use async requests after send first msg consumer get it normaly first time, when we send next msg consumer get first msg and stop working.

What we do wrong?

P.S.
As you see we use Kafka 1.0.0.0. PHP 7.1
Consumers on Java