Horizontal Scroll on Gallery (manual scrolling)

Dear Webflow Community,

I’m new to Webdesign and I’ve a simple Problem that I just can’t seem to fix:

In the Image Gallery in “Section 1 (Hero) / GalleryHZ” I’m trying to implement the Horizontal Scroll effect however I would like the Gallery to also be scrollable horizontally manually.
I’ve tried a HTML Embed adding the following code:

<style>
.GWRAP {
 overflow-x: auto;
 white-space: nowrap;
   }
 </style>

It doesn’t seem to work though.

I’ve tried the same thing on a blank website recreating the problem with the exact same HTML Embed and there it seems to work just fine:

I’ve ruled out the following problems by experementing:
-I tried turning off Interactions
-I tried placing the HTML Embed in almost any sensible location
-I tried taking the Gallery out of its Parent Element positioning it right underneath the Body Tag so I don’t think that the Parent Divs have anything to do with it.

I bet it is a really simple solution but I just can’t wrap my head around could someone please take a look ?

Thanks
David