Uploading video onto Facebook using Facebook PHP SDK gives me no error but no video uploaded?

I'm trying to Post a video onto Facebook using Facebook php SDK and Facebook graph and I get a strange response back.

it shows a success but null video ID!

This is the response I get:

{"video_id":null,"success":true}

And this is my code:

$fb = new Facebook\Facebook([
    'app_id' => 'XXX',
    'app_secret' => 'XXXXX',
    'default_graph_version' => 'v2.9',
]);
$accessToken = 'XXXXXX';


try {
    $videoTitle = 'FOO';
    $videoDescription = 'BAR';
    $data = [
      'title' => $videoTitle,
      'description' => $videoDescription,
    ];

  $response = $fb->uploadVideo('/me/', '/var/www/vhosts/SITE.co.uk/httpdocs/video.mp4', $data, $accessToken);
    
    

    
} catch(Facebook\Exception\ResponseException $e) {
  // When Graph returns an error
  echo 'Graph returned an error: ' . $e->getMessage();
  exit;
} catch(Facebook\Exception\SDKException $e) {
  // When validation fails or other local issues
  echo 'Facebook SDK returned an error: ' . $e->getMessage();
  exit;
}

//echo 'Video ID: ' . $response; 

echo json_encode($response);

I don't know whats causing this and I have spent hours trying to figure this out.

any help would be appreciated.