PayPay IPN Verification Invalid

[MsWord]

Hallo zusammen.

ich habe ein Problem mit meinem PayPal Script.
Den IPN listener habe ich von der Original PayPal github Seite.

<?php
class PaypalIPN
{
    /** @var bool Indicates if the sandbox endpoint is used. */
    private $use_sandbox = false;
    /** @var bool Indicates if the local certificates are used. */
    private $use_local_certs = true;
    /** Production Postback URL */
    const VERIFY_URI = 'https://ipnpb.paypal.com/cgi-bin/webscr';
    /** Sandbox Postback URL */
    const SANDBOX_VERIFY_URI = 'https://ipnpb.sandbox.paypal.com/cgi-bin/webscr';
    /** Response from PayPal indicating validation was successful */
    const VALID = 'VERIFIED';
    /** Response from PayPal indicating validation failed */
    const INVALID = 'INVALID';
    /**
     * Sets the IPN verification to sandbox mode (for use when testing,
     * should not be enabled in production).
     * @return void
     */
    public function useSandbox()
    {
        $this->use_sandbox = true;
    }
    /**
     * Sets curl to use php curl's built in certs (may be required in some
     * environments).
     * @return void
     */
    public function usePHPCerts()
    {
        $this->use_local_certs = false;
    }
    /**
     * Determine endpoint to post the verification data to.
     *
     * @return string
     */
    public function getPaypalUri()
    {
        if ($this->use_sandbox) {
            return self::SANDBOX_VERIFY_URI;
        } else {
            return self::VERIFY_URI;
        }
    }
    /**
     * Verification Function
     * Sends the incoming post data back to PayPal using the cURL library.
     *
     * @return bool
     * @throws Exception
     */
    public function verifyIPN()
    {
        if ( ! count($_POST)) {
            throw new Exception("Missing POST Data");
        }
        $raw_post_data = file_get_contents('php://input');
        $raw_post_array = explode('&', $raw_post_data);
        $myPost = array();
        foreach ($raw_post_array as $keyval) {
            $keyval = explode('=', $keyval);
            if (count($keyval) == 2) {
                // Since we do not want the plus in the datetime string to be encoded to a space, we manually encode it.
                if ($keyval[0] === 'payment_date') {
                    if (substr_count($keyval[1], '+') === 1) {
                        $keyval[1] = str_replace('+', '%2B', $keyval[1]);
                    }
                }
                $myPost[$keyval[0]] = urldecode($keyval[1]);
            }
        }
        // Build the body of the verification post request, adding the _notify-validate command.
        $req = 'cmd=_notify-validate';
        $get_magic_quotes_exists = false;
        if (function_exists('get_magic_quotes_gpc')) {
            $get_magic_quotes_exists = true;
        }
        foreach ($myPost as $key => $value) {
            if ($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) {
                $value = urlencode(stripslashes($value));
            } else {
                $value = urlencode($value);
            }
            $req .= "&$key=$value";
        }
        // Post the data back to PayPal, using curl. Throw exceptions if errors occur.
        $ch = curl_init($this->getPaypalUri());
        curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
        curl_setopt($ch, CURLOPT_SSLVERSION, 6);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
        // This is often required if the server is missing a global cert bundle, or is using an outdated one.
        if ($this->use_local_certs) {
            curl_setopt($ch, CURLOPT_CAINFO, __DIR__ . "/cert/cacert.pem");
        }
        curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'User-Agent: PHP-IPN-Verification-Script',
            'Connection: Close',
        ));
        $res = curl_exec($ch);
        if ( ! ($res)) {
            $errno = curl_errno($ch);
            $errstr = curl_error($ch);
            curl_close($ch);
            throw new Exception("cURL error: [$errno] $errstr");
        }
        $info = curl_getinfo($ch);
        $http_code = $info['http_code'];
        if ($http_code != 200) {
            throw new Exception("PayPal responded with http code $http_code");
        }
        curl_close($ch);
        // Check if PayPal verifies the IPN data, and if so, return true.
        if ($res == self::VALID) {
            return true;
        } else {
            return false;
        }
    }
}

Ich bekomme aber leider NUR im live Betrieb immer zur verification "invalid" zurück. (In der Sandbox und über den IPN listener Simulator funktioniert es)
Ich habe es auch schon wie auf der Webseite von PayPal Developer steht die urlencode/decode durch rawurlencode/... ersetzt.

Leider will das im Live Betrieb nicht funktionieren... hat jemand damit Erfahrungen gemacht?

P.S. Der Listener ist richtig in den Einstellungen im PayPal Konto hinterlegt. Und https nutze ich ebenfalls.