title: Lazysizes bgset not changing image on resize
body: <p>Im using Lazysizes on a Shopify Store, but I've noticed that the background images do no change to smaller sizes when the screen size gets to the preset on the data-bgset. I've followed the whole documentation but I see no change on the image when the size of the screen is below one of the set widths on the data-bgset. Here is the code for the image:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div class ="collection-grid-item__overlay box ratio-container lazyload"
      data-bgset ="//cdn.shopify.com/s/files/1/2513/1014/collections/toallas_1_180x.png?v=1557940674 180w,
      //cdn.shopify.com/s/files/1/2513/1014/collections/toallas_1_360x.png?v=1557940674 360w,
      //cdn.shopify.com/s/files/1/2513/1014/collections/toallas_1_400x.png?v=1557940674 450w,
      //cdn.shopify.com/s/files/1/2513/1014/collections/toallas_1.png?v=1557940674 500w"
      data-sizes ="auto"
      data-parent-fit ="cover"
      &gt;
  &lt;/div&gt;
  &lt;noscript&gt;
  &lt;div class="collection-grid-item__overlay" style="background-image: url('{{ collection_image | img_url: '1024x1024' }}')"&gt;&lt;/div&gt;
  &lt;/noscript&gt;
  </code></pre>
  
  <p>I have correctly set up the LazySizes js and the plugin for bg and respimg js like in the documentation. The site in question is <a href="https://tiendadepend.mx" rel="nofollow noreferrer">https://tiendadepend.mx</a> and the images are in the section after "¿FUGAS DE ORINA? CONOCE NUESTROS PRODUCTOS" title. These images are the ones which do no change on load. Any ideas what I could try to fix that? </p>