curl not downloading all pdf files PHP - php

Question

im trying to download multiple pdfs with php. i get an array of urls and each url redirects to a website that contains a pdf file if something is wrong with that url it just redirects to a html page, so i've been googling and found this to download all pdfs to the server:
public function download ($data, $simultaneous = 1, $save_to)
{
$loops = array_chunk($data, $simultaneous, true);
foreach ($loops as $key => $value)
{
foreach ($value as $urlkey => $urlvalue)
{
$ch[$urlkey] = curl_init($urlvalue["url"]);
curl_setopt($ch[$urlkey], CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch[$urlkey], CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch[$urlkey], CURLOPT_SSL_VERIFYHOST, false);
}
$mh = curl_multi_init();
foreach ($value as $urlkey => $urlvalue)
{
curl_multi_add_handle($mh, $ch[$urlkey]);
}
$running = null;
do {
curl_multi_exec($mh, $running);
} while ($running);
foreach ($value as $urlkey => $urlvalue)
{
$response = curl_multi_getcontent($ch[$urlkey]);
file_put_contents($save_to.$urlvalue["saveas"], $response);
curl_multi_remove_handle($mh,$ch[$urlkey]);
curl_close($ch[$urlkey]);
}
}
}
for some reason this downloads only some of the files
anyone has any idea why this is not working?
any help would be appreciated