ajax reply working but when it load second times - ajax

Question

I am updating my cart quantity using ajax. After successfully updating of the cart, when I load the cart and body of the current page the toggle menu of the my cart button does not work the first time. But when I update second time after loading the cart and body the toggle menu works.
My current code:
'remove': function(product_id, flag) {
// alert(product_id);
// alert(flag);
$.ajax({
url: 'includes/addToCart.php',
type: 'post',
data: 'product_id=' + product_id + '&flag='+flag,
dataType: 'json',
beforeSend: function() {
$('#cart > button').button('loading');
},
complete: function() {
$('#cart > button').button('reset');
},
success: function(json) {
// Need to set timeout otherwise it wont update the total
setTimeout(function () {
$('#cart > button').html('<span class="lg">My Cart</span><span><i class="fa fa-shopping-basket"></i> ('+json['total']+') items</span>');
}, 100);
setTimeout(function () {
// if(json['key'] == "blank")
$('#cart > ul').load('includes/loadcart.php');
}, 100);
setTimeout(function () {
$('body').load('cart.php');
}, 100);
},
});
In the console I am getting this error when it executes:
Synchronous XMLHttpRequest on the main thread is deprecated because of
its detrimental effects to the end user’s experience.
I have used the async: true, and async: false
same problem persists
here is my html code where the value displayed
<div class="btn-group btn-block" id="cart">
<button class="btn btn-viewcart dropdown-toggle" data-loading-text="Loading..." data-toggle="dropdown" type="button" aria-expanded="false" id="cart_total"><span class="lg">My Cart</span><span><i class="fa fa-shopping-basket"></i> (<?=$_SESSION['totalitem']?>) items</span></button>
<ul class="dropdown-menu pull-right" ><li>
<table id="cart_item" class="table table-striped">
<tbody>
<?php
if(empty($_SESSION['cart'])){
?>
<tr>
<td align="center" style="font-weight: bold; font-size: 14px;" colspan="5">Your Cart Is empty</td>
</tr>
<?php
}
else{
$subtotal = 0;
foreach($_SESSION['cart'] as $key=>$value){
$subtotal = $subtotal + ($_SESSION['cart'][$key]['price']*$_SESSION['cart'][$key]['qty']);
?>
<tr>
<td class="text-center"> <img class="img-thumbnail" title="iPhone" alt="iPhone" src="../photo/<?=$_SESSION['cart'][$key]['img']?>" width="57px" height="57px">
</td>
<td class="text-left"><?=$_SESSION['cart'][$key]['name']?>
</td>
<td class="text-right">x <?=$_SESSION['cart'][$key]['qty']?></td>
<td class="text-right">$<?=$_SESSION['cart'][$key]['price']*$_SESSION['cart'][$key]['qty']?></td>
<td class="text-center"><button class="btn btn-danger btn-xs" title="Remove" onclick="cart.remove('<?=$_SESSION['cart'][$key]['id']?>','delete');" type="button"><i class="fa fa-times"></i></button></td>
</tr>
<?php
}
}
$vat= $subtotal * (20/100);
$total = $subtotal + $vat;
?>
</tbody></table>
</li><li>
<?php
if(!empty($_SESSION['cart']))
{
?>
<div>
<table class="table table-bordered">
<tbody><tr>
<td class="text-right"><strong>Sub-Total</strong></td>
<td class="text-right">$<?=$subtotal?></td>
</tr>
<tr>
<td class="text-right"><strong>Eco Tax (-2.00)</strong></td>
<td class="text-right">$2.00</td>
</tr>
<tr>
<td class="text-right"><strong>VAT (20%)</strong></td>
<td class="text-right">$<?=$vat?></td>
</tr>
<tr>
<td class="text-right"><strong>Total</strong></td>
<td class="text-right">$<?=$total?></td>
</tr>
</tbody></table>
<p class="text-right"><strong><i class="fa fa-shopping-cart"></i> View Cart</strong> <strong><i class="fa fa-share"></i> Checkout</strong></p>
</div>
<?php
}
?>
</li></ul>
</div>