Hi @canis_orion,
This scrollbar is the default tool of the browser. It cannot be removed by css. It must be added the .js also. Even when adding the .js, the scrollbar is required to drag it horizontally. So, it is just added the css to hide this scrollbar when not hovering into that box.
My coder has added .js and css in the Theme Options. You should backup the code if you want to update the theme in the future.
When you do not hover on this box, it will display like this: https://prnt.sc/umbjex And when you hover the mouse on this, the scrollbar will display like this: https://prnt.sc/umbjx6
Pls check your site again then let me know
Regards,
Yame