Почему блокируется URL?

function get_partner_price($url, $partner){
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    $html = curl_exec($ch);
    curl_close($ch);
    switch($partner){
        case 'expert':
            $result = [];
            $classname = 'product__price-count';
            $domdocument = new DOMDocument('1.0', 'utf-8');
            @$domdocument->loadHTML($html);
            $a = new DOMXPath($domdocument);
            $spans = $a->query("//*[contains(concat(' ', normalize-space(@class), ' '), ' $classname ')]");
            for ($i = $spans->length - 1; $i > -1; $i--) {
                $result[] = utf8_decode($spans->item($i)->firstChild->nodeValue);
            }
            $price = $result[0];
            if($price == null) { return null; }
            break;

        case 'spets':
            $doc = new DOMDocument();
            @$doc->loadHTML($html);
            $price=$doc->getElementById('priceOffers')->nodeValue;
            if($price == null) { return null; }
            break;

        case 'sirius':
            $result = [];
            $classname = 'price-opt';
            $doс = new DOMDocument('1.0', 'utf-8');
            @$doс->loadHTML($html);
            $a = new DOMXPath($doс);
            $spans = $a->query(
                "//*[contains(concat(' ', normalize-space(@class), ' '), ' $classname ')]/span"
            );
            for ($i = $spans->length - 1; $i > -1; $i--) {
                $result[] = utf8_decode($spans->item($i)->firstChild->nodeValue);
            }
            $price = $result[12];
            if($price == null) { return null; }
            break;

        default:
            $price = null;
            break;
    }
    return $price;

}