wp_is_mobile和wp_redirect无效

I am encountering some problems with the wp_redirect and wp_is_mobile functions, on my Wordpress.

I have to pages :

The mobile form page, that is working fine :

<?php
  if (!is_mobile())
  {
    wp_redirect( 'MY URL', 301 ); // Redirect to the non-mobile version of the form
    exit;
  }
?>
// My html form

The non-mobile form page, that won't redirect : (For securities reasons, I currently removed the redirection script)

<?php
  if (wp_is_mobile())
  {
    wp_redirect( 'MY URL', 301 ); // Redirect to mobile version of the form
    exit;
  }
?>
// My html form

BUT... the local (WAMP) version of this page is working.

Also, i tried to make a page without any HTML code, where the redirecting does work in both cases :

<?php
 if (is_mobile())
  {
   wp_redirect( 'MY URL', 301 );
   exit;
  }
 else
  {
   wp_redirect( 'MY URL', 301 );
   exit;
  }
?>

Thank you for your help.

Well, all I had to do is to recreate the wordpress page. It seems to work fine, now. thanks anyway !