What is the problem with AWS SessionHandler?

Question

PHP

Greetings!
There is an application on Phalcon framework. Sessions are stored using 'DynamoDB' and `SessionHandler` from AWS.
Code -

$di['session'] = function () {
    $config = $this->getShared('config');

    if(ENV != 'local'){
        $credentials = new \Aws\Credentials\Credentials($config->amazon->AWSAccessKeyId, $config->amazon->AWSSecretKey);

        $dynamoDb = new DynamoDbClient([
            'credentials' => $credentials,
            'region' => $config->amazon->Region,
            'version' => 'latest',
        ]);

        $sessionHandler = SessionHandler::fromClient($dynamoDb,[
            'table_name'    => $config->amazon->sessionTable
        ]);

        $sessionHandler->register();
    }

    $session = new Phalcon\Session\Adapter\Files();
    $session->start();

    return $session;
};

Problem -
Appeared after updating php from 5.6 to 7.2 and AWS SDK from 2.8 to 3.9
In the local environment, everything works fine, but when rolled out to the test environment, the session initialization falls off.
At the time of execution - the $session->start();
page falls off with a 503 error (Gateway Time-Out).
PHP Version - 7.2.18
Phalcon: -3.4.4
AWS SDK - 3.98.

phpinfo() local

phpinfo() test environment

only in the test environment the value `session.save_handler` = user. But even after changing to files, nothing worked.
PS I do not have access to the logs, only deploy through the repository
I would be grateful for any help!