As part of a Reviews Lightbox Integration, a Feefo badge is added to the website. When the badge is clicked, a separate window (or lightbox) appears which should overlay all other visible content. Occasionally, when a user clicks on the badge the generated lightbox renders but some of the other content on the site is overlaying over the Feefo lightbox. 

This is typically caused by the z-index of the CSS styling that's applied to the content. The JavaScript integration code uses a z-index of 99999 so anything higher than this will overlap the lightbox content.

To solve this problem, set the z-index of other content to have a lower value than 99999.