Unable to complete SSL/TLS handshake and set local cert chain file - php

Question

I can create a ssl key and certificate with the following script:
<?php
$name='example_ss'; //Will add _key.pem, _crt.pem, _csr.pem
$data = [
"countryName" => "US",
"stateOrProvinceName" => "CA",
"localityName" => "San Francisco",
"organizationName" => "example.net",
"organizationalUnitName" => "example.net",
"commonName" => "example.net",
"emailAddress" => "exampleATgmailDOTcom"
];
$pem_passphrase = 'secret';
// Generate certificate
$key = openssl_pkey_new();
$csr = openssl_csr_new($data, $key);
$csr = openssl_csr_sign($csr, null, $key, 365);
// Generate PEM file
$pem = [];
openssl_x509_export($csr, $pem[0]);
file_put_contents($name.'_crt.pem', $pem[0]);
//openssl_pkey_export($key, $pem[1], $pem_passphrase); //Remove $pem_passphrase for none
openssl_pkey_export($key, $pem[1]); //Remove $pem_passphrase for none
$pem = implode($pem);
file_put_contents($name.'_key.pem', $pem);
Move them as required:
sudo mv example_ss_crt.pem /etc/pki/tls/certs/example_ss_crt.pem
sudo mv example_ss_key.pem /etc/pki/tls/private/example_ss_key.pem
And everything works find.
But when I create them manually: (w/ and w/o using -sha256)
openssl req -x509 -newkey rsa:4096 -keyout example_ss_key.pem -out example_ss_crt.pem -days 365 -nodes
And move them as I did for the previous, I get the following error:
Unable to complete SSL/TLS handshake: stream_socket_enable_crypto():
Unable to set local cert chain file `/etc/pki/tls/private/example_ss_key.pem';
Check that your cafile/capath settings include details of your certificate and its issuer
What is the difference between these two sets of keys and how do I create them manually? I don't think it is relevant, but they are being used for a tcp sockets connection between Centos7 and a Raspberry Pi.
EDIT. The server is created with the following script. I am not using a passphrase.
$loop = \React\EventLoop\Factory::create();
$server = new \React\Socket\TcpServer($this->host['url'].':'.$this->host['port'], $loop);
if($this->host['tls']) {
$server = $this->host['privateKey']
?new \React\Socket\SecureServer($server, $loop, ['local_cert' => $this->host['privateKey'],'passphrase' => $this->host['passphrase'] ])
:new \React\Socket\SecureServer($server, $loop, ['local_cert' => $this->host['privateKey'] ]);
}
Dummy mistake. http://php.net/manual/en/context.ssl.php
local_cert string Path to local certificate file on filesystem. It
must be a PEM encoded file which contains your certificate and private
key. It can optionally contain the certificate chain of issuers. The
private key also may be contained in a separate file specified by
local_pk
.