Lightbox not showing full size

Hi I’m having a problem with Enfold’s lightbox, I tried looking at the jquery files but the variables look like such gibberish to me.

The problem is that this lightbox doesn’t show the full size image, sometimes the lightbox is actually smaller than the image displayed in the page (as is the case in my link), I want it to take advantage of all available window space to give the viewer the biggest image it can.

I already tried this solution I found in some other thread but it didn’t make a difference:

// lightbox fullsize
function lightbox_fullsize(){
?>
<script>
    jQuery(document).ready(function() {         
      jQuery('.avia-gallery-thumb').on('click',' a',function(){
         jQuery(document).find('.mfp-wrap figure img').css("max-height","");
         console.log(' child Lightbox img ');               
      });
    });
</script>
<?php
}
add_action('wp_head', 'lightbox_fullsize');