Posts Carousel – no arrow on mobile

I have implemented the Posts Carousel at the top of the page, but on mobile phone there is no arrow to indicate to swipe to see more. I have ARROWS enabled, but they don’t show on either desktop or mobile. We’re especially concerned with mobile, because it only shows one of the three images, so how do they know to swipe to see more?

The page I need help with: [log in to see the link]