Why are the hashes received after paying with Perfect Money different?

Question

PHP

I thought for a long time why the payment processor does not work. I thought that PM did not send anything back at all.
Decided to check. Caught all $_POST and scored in the database. Everything comes.
Compared $_POST["V2_HASH"] and calculated on the server - they are different. What could be the problem?

define('ALTERNATE_PHRASE_HASH',  '%фраза%');
$string=
      $_POST['PAYMENT_ID'].':'.$_POST['PAYEE_ACCOUNT'].':'.
      $_POST['PAYMENT_AMOUNT'].':'.$_POST['PAYMENT_UNITS'].':'.
      $_POST['PAYMENT_BATCH_NUM'].':'.
      $_POST['PAYER_ACCOUNT'].':'.ALTERNATE_PHRASE_HASH.':'.
      $_POST['TIMESTAMPGMT'];
$hash=strtoupper(md5($string));

I pay from my wallet to my own, but in fact, this should not affect.

Answer 1

The fact that you incorrectly consider the hash.