Can't get output from process

[sandrokeil]

I can't get the response from the process, independent of sync or async call. I use Socket connection and the access log looks good so far. Here is the "worker script":

<?php

declare(strict_types=1);

echo "Hello World";

The response with async is � and on sync '' . "\0" . '' . "\0" . ''. Looks like the stream can not be read successfully.