using youtubes api on a website which runs on a raspberry pi - php

Question

I use the youtube api to search for videos on my own page. That works so far quite well, as long as I access the site via localhost. I use PHPStorms build-in-server (which basically is xampp) to connect via localhost to the website. But if I run the page on my Raspberry Pi and do the same search, about 90% of the videos shows the following error: "video not available".
This is the code for the api
<?php
if (isset($_POST['submit']) )
{
if (!empty($keyword))
{
$keyword = str_replace(' ', '',$keyword);
$apikey = ' '; // i removed the key
$googleApiUrl = 'https://www.googleapis.com/youtube/v3/search?part=snippet&q=' . $keyword . '&maxResults=' . MAX_RESULTS . '&key=' . $apikey;
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $googleApiUrl);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$response = curl_exec($ch);
curl_close($ch);
$data = json_decode($response);
$value = json_decode(json_encode($data), true);
?>
<div class="result-heading">About <?php echo MAX_RESULTS; ?> Results</div>
<div class="videos-data-container" id="SearchResultsDiv">
<?php
for ($i = 0; $i < MAX_RESULTS; $i++) {
if (!empty($value['items'][$i]['id']['videoId'])) {
$videoId = $value['items'][$i]['id']['videoId'];
$title = $value['items'][$i]['snippet']['title'];
$description = $value['items'][$i]['snippet']['description'];
?>
<div class="video-tile">
<div class="videoDiv">
<iframe id="iframe" style="width:100%;height:100%"
src="//www.youtube.com/embed/<?php echo $videoId; ?>"
data-autoplay-src="//www.youtube.com/embed/<?php echo $videoId; ?>?autoplay=1"></iframe>
</div>
<div class="videoInfo">
<div class="videoTitle"><b><?php echo $title; ?></b></div>
<div class="videoDesc"><?php echo $description; ?></div>
</div>
</div>
<?php
}
}
}
}
?>
</div>
does anyone know why it works on localhost but not on the raspberry pi?