使用Ajax提交兩次表單

我試圖使用Ajax提交表單，但是它提交了兩次輸入的值。你能幫我防止這個問題嗎？我試著從前面的問題中提出了幾個建議，但都沒有奏效。

Thank you

Html Code:

<form id="ratingForm" method="POST">
    <div class="form-group">
        <h4>Rate this product</h4>
        <!-- Start Star -->
        <button type="button" class="btn btn-warning btn-sm rateButton" aria-label="Left Align">
          <span class="glyphicon glyphicon-star" aria-hidden="true"></span>
        </button>
        
        <button type="button" class="btn btn-default btn-grey btn-sm rateButton" aria-label="Left Align">
          <span class="glyphicon glyphicon-star" aria-hidden="true"></span>
        </button>
        
        <button type="button" class="btn btn-default btn-grey btn-sm rateButton" aria-label="Left Align">
          <span class="glyphicon glyphicon-star" aria-hidden="true"></span>
        </button>
        
        <button type="button" class="btn btn-default btn-grey btn-sm rateButton" aria-label="Left Align">
          <span class="glyphicon glyphicon-star" aria-hidden="true"></span>
        </button>
        
        <button type="button" class="btn btn-default btn-grey btn-sm rateButton" aria-label="Left Align">
          <span class="glyphicon glyphicon-star" aria-hidden="true"></span>
        </button>
        <!-- End Star -->

        <input type="hidden"  id="rating" name="rating" value="1">
        <input type="hidden"  id="itemId" name="itemId" value="<?php echo $_GET['id']; ?>">
        <input type="hidden" name="action" value="saveRating">
    </div>      
    <div class="form-group">
        <!--Comment Start-->
        <label for="usr">Title*</label>
        <input type="text"  id="title" name="title" required>
    </div>
    <div class="form-group">
        <label for="comment">Comment*</label>
        <textarea rows="5" id="comment" name="comment" required></textarea>
    </div>
    <div class="form-group">
        <button type="submit" class="btn btn-info" id="saveReview">Save Review</button>
    </div>
     <!--Comment End-->          
</form>

Js Code:

$('#ratingForm').on('submit', function(event){
  event.preventDefault();
  event.stopImmediatePropagation();
    var formData = $(this).serialize();
    $.ajax({
        type : 'POST',
        dataType: "json",   
        url : 'action.php',                 
        data : formData,
        success:function(response){
            if(response.success == 1) {
                $("#ratingForm")[0].reset();
                window.location.reload();
            }
        }
    }); 
});

Php代碼（這是action.php文件）：Execution.php文件使用mysql將數(shù)據(jù)插入數(shù)據(jù)庫。

<?php
session_start();
include 'class/Execution.php';
$rating = new Rating();

if(!empty($_POST['action']) && $_POST['action'] == 'saveRating'  
    && !empty($_POST['rating']) 
    && !empty($_POST['itemId'])) {
        $rating->saveRating($_POST, $_SESSION['userId']);   
        $data = array(
            "success"   => 1,   
        );
        echo json_encode($data);        
}

?>