循环和回显除第一个子节点之外的div除其父div之外的结果

as the title says I loop several divs which is supposed to be inside their parent but only the first child is inside

there are 2 php file, one is the template the other is for generating content

here are php code :

The Template

<div class="badan">
  <?php include "isi.php" ?>
</div>

The Content (isi.php)

$sql=mysqli_query($con,"SELECT * FROM produk WHERE id_kategori2='4' ORDER BY id_produk DESC LIMIT 4"); 
echo "<div class='produk-box'>"; 

while ($r=mysqli_fetch_array($sql)){

  include "diskon_stok.php";

  echo "<div class='produk'>
        <div class='produk-title'><a href='produk-$r[id_produk]-$r[produk_seo].html'>$r[nama_produk]</a></div>
        <br />
        <a href='produk-$r[id_produk]-$r[produk_seo].html'><img class='produkimg' src='../foto_produk/small_$r[gambar]' title='$r[nama_produk]'></a>
        $divharga
    </div>";
    }
  echo"</div>";

now the parent is div class=badan while the childs are div class=produk-box and the level 2 child is div class=produk my intention is to make all of produk echoed inside produk-box while produk-box is echoed inside badan

but what's really happening is the first produk is echoed INSIDE produk-box, the second produk is echoed OUTSIDE of its parent div, and the rest of produk is echoed OUTSIDE of badan

here is the screenshot of google chrome inspect element :

echo "<div class='produk-box>'";

should be

echo '<div class="produk-box">';