Fixing 'echo' of descriptions on carousel

I've adapted a gallery page with the following code, to display the descriptions. However, there's a slight echo when flipping through the images (see attached video). Anyone who would know how to fix this?

<script>
/**
 * Add descriptions/captions to galleries in Squarespace 7.1.
 * JavaScript 
 * © @brandon (Squarespace Forum User)
 * This software is provided "as is", without warranty of any kind, express or implied.
 */
document.addEventListener("DOMContentLoaded", function() {
  addGalleryItemDescriptions();
    
  function addGalleryItemDescriptions(gs, gdzs) {
    var a=['querySelectorAll','section.gallery-section-exclude,\x20.gallery-lightbox','length','[class*=\x27-item\x27]:not([class*=\x27item-\x27])','getElementsByTagName','img','alt','trim','createElement','div','className','gallery-item-description','textContent','appendChild'];var b=function(c,d){c=c-0x0;var e=a[c];return e;};(function(c,d){var e,f,g,h,i,j,k;e=document[b('0x0')](c?c:b('0x1'));i=e[b('0x2')];while(i--){f=e[i][b('0x0')](d?d:b('0x3'));j=f[b('0x2')];while(j--){g=f[j][b('0x4')](b('0x5'))[0x0][b('0x6')][b('0x7')]();if(g){h=document[b('0x8')](b('0x9'));h[b('0xa')]=b('0xb');h[b('0xc')]=g;f[j][b('0xd')](h);}}}}(gs,gdzs));
  }
});
</script>

Hi. The gallery section supported description, no need to use code.

You can edit gallery section > enable caption.

Unfortunately, it doesn't work in the lightbox. I prefer the captions not to be displayed in the gallery, and only when opened in the carousel. The descriptions are there now, but the 'echo' is causing problems. Any chance you know how to fix it?