Po moich modyfikacjach kod wygląda tak:
if (preg_match('/<trans>\s*<id>(\d+)<\/id>\s*<session>(.*?)<\/session>\s*<order_id>(.*?)<\/order_id>\s*<amount>(\d+)<\/amount>\s*<status>(\d+)<\/status>\s*<desc>(.*?)<\/desc>\s*<ts>(\d+)<\/ts>\s*<sig>([a-z0-9]*)<\/sig>\s*<\/trans>/si', $platnosci_response, $parts)); $result = get_status($parts);
Niestety tablica jest pusta

$platnosci_response:
<?xml version="1.0" encoding="ISO-8859-2"?>
<response>
<status>OK</status>
<trans>
<id>1111111111</id>
<pos_id>2222222222</pos_id>
<session_id>5b90e4</session_id>
<order_id>5b90e/order_id>
<amount>2325</amount>
<status>99</status>
<pay_type>o</pay_type>
<pay_gw_name>pe</pay_gw_name>
<desc>cukiernia@domena.pl</desc>
<desc2></desc2>
<create>2018-09-06 10:27:25</create>
<init>2018-09-06 10:28:24</init>
<sent>2018-09-06 10:28:25</sent>
<recv>2018-09-06 10:28:25</recv>
<cancel></cancel>
<auth_fraud>0</auth_fraud>
<ts>1536251379151</ts>
<sig>b5a5a07f6198a778100adddf</sig>
<add_client_street></add_client_street>
<add_client_post_code></add_client_post_code>
<add_client_address></add_client_address>
<add_client_account>53124027601608</add_client_account>
<add_cc_number_hash>ab7205a7e780824537516</add_cc_number_hash>
<add_client_name></add_client_name>
<add_client_city></add_client_city>
</trans>
</response>