PHP - Header redirect issue Occur in Live Server

Method I
<?php
ob_start();
if(isset($_GET['elimina_id'])){
 if (in_array($_GET['elimina_id'], $_SESSION['cart']) ) {
  $index = (array_keys($_SESSION['cart'], $_GET['elimina_id']));
  $i = $index[0];
  unset($_SESSION['cart'][$i]);
  header('location: cart.php');
 }
}
ob_end_flush();
?> 


Method II
HTML: <meta http-equiv="refresh" content="0;url=http://www.site.com/cart.php">
JavaScript #1: <script>window.location = "http://www.site.com/cart.php";</script>
JavaScript #2: <script>window.navigate("http://www.site.com/cart.php");</script>