Strange behavior of cURL request in PHP script

I am experiencing strange behavior of a cURL request that I am making in my PHP code. I am running the code locally on a standard WAMP Apache server. Here's the code:

$auth_info = "...";
$some_url = "...";
$channel = curl_init();
curl_setopt($channel, CURLOPT_URL, $some_url);
curl_setopt($channel, CURLOPT_HTTPHEADER, 
    array("Authorization: BASIC " . base64_encode($auth_info))
);
curl_setopt($channel, CURLOPT_RETURNTRANSFER, true);
curl_setopt($channel, CURLOPT_HEADER, true);
$response = curl_exec($channel);
var_dump(curl_getinfo($channel));
$header_size = curl_getinfo($channel, CURLINFO_HEADER_SIZE);
$header = substr($response, 0, $header_size);
$body = substr($response, $header_size);
var_dump($header);
var_dump($body);
curl_close($channel);

      

        
        
        
      

    

If I execute this little PHP code snippet through my CLI (Powershell since I am on Windows) everything is fine , all var_dumps are working and I can see the $ header and $ body and everything and the data I expect is really are present.

Now for the weird behavior. If I open the script file with the above snippet in any browser it just gives me:

array (size=26)
'url' => string 'the_url_here' (length=39)
'content_type' => null
'http_code' => int 0
'header_size' => int 0
'request_size' => int 0
'filetime' => int -1
'ssl_verify_result' => int 0
'redirect_count' => int 0
'total_time' => float 1.234
'namelookup_time' => float 0
'connect_time' => float 0.109
'pretransfer_time' => float 0
'size_upload' => float 0
'size_download' => float 0
'speed_download' => float 0
'speed_upload' => float 0
'download_content_length' => float -1
'upload_content_length' => float -1
'starttransfer_time' => float 0
'redirect_time' => float 0
'redirect_url' => string '' (length=0)
'primary_ip' => string 'here_is_the_ip' (length=12)
'certinfo' => 
  array (size=0)
    empty
'primary_port' => int 443
'local_ip' => string 'here_is_my_ip' (length=13)
'local_port' => int -> my_local_port_here
boolean false
boolean false

      

        
        
        
      

    

I am completely puzzled as I cannot see the difference between script beeing running CLI and running browser. Anyone got an idea about this?

EDIT Note. If I use Guzzle for the request, everything works fine, both in the CLI and in the browser. I'm still interested in the answer why cURL is causing problems here.