Zoom appears behind an product image

The zoom effect shows behind single product image.
I see in footer it has inline style

<div style=”-webkit-transform: translateZ(0px); position: absolute; left: 822.5px; top: 315px; height: 400px; width: 400px;”>

if i add z-index 999 it works, but can’t find way to add it in jquery.image_zoom.min.js
if i am adding z-index there, somehow it stops working.

any thoughts

https://www.ads-software.com/plugins/wp-image-zoooom/