Wow Carasoul divi lite navigation arrows

Hi, Divi support recommended your plugin which is great thanks. However when I make the navigation arrows (left and right arrows either side of the photos) this makes the right arrow too far out? So not equally spaced from the images. See this page to see what I mean thanks – https://waveneyvalleybarn.co.uk/the-barn/ (a site nearly ready for completion this week). Scroll down to where I have added the galley, the right arrow needs to be the same distance away from the images as the left one is. I can’t seem to see why it’s doing it. Could someone help please?

Also will I need to disable this gallery for mobile as it doesn’t show the arrows on mobile and recreate one specially for mobile devices?

Thank you for your help!