Laravel 5 Facebook Signed request function to get page id

I have a page tab application where I get the page id from a signed request. To get the page i call this function.

$facebook_page_id = get_Fb_Page_Id();

The problem is that this only works the first time I call the function. Why is this?

En exmaple would be that I have a startpage which returns some results but also a page that returns search results. The function only works on the startpage but not when returning search results.

Here is my function.

function get_Fb_Page_Id() {

$fb = App::make('SammyK\LaravelFacebookSdk\LaravelFacebookSdk');
$helper = $fb->getPageTabHelper();

try {
    $token = $fb->getCanvasHelper()->getAccessToken();
} catch (Facebook\Exceptions\FacebookSDKException $e) {
    // Failed to obtain access token
    dd($e->getMessage());
}

// $token will be null if the user hasn't authenticated your app yet
if (! $token) {
    // . . .
}

$id = $helper->getPageId();

return $id;

}

via Chebli Mohamed