displaying products using ajax in codeigniter php issue

i have a products page , where products are displayed inside the div using ajax, the code is like below:

$.ajax({
  url: "<?php echo base_url();?>homecontroller/viewajax",
  type: "POST",
  data: {
    id: <?=$idz?>
  },
  cache: false,
  success: function(data) {
    //alert(data);
    $('#marble').html(data);
  }
});

<div class="row mt-30-reverse" id="marble">


</div>

the issue here is the products are displaying correctly sometimes but most times the products are hidden, white space is shown, but when u hover on that white space thehidden products are hoverable, can anyone please tell me whats wrong in here, thanks in advance