I have the gallery box to Show Recent Media on Forum List. I notice on some sites they have right and left arrows that show when you hover over the images on the ends to scroll. I don't have that. Any ideas?
On your alien forum, though, they aren't visible and that's as designed - you only have 5 images showing, and at a desktop/laptop display width it can fit all 5 images in, so there's no need for the navigation arrows. Resize your browser on that site, however, and the arrows do appear as the number of images displays falls below 5.
That said, the colour of the arrows is making them very difficult to see, so this is perhaps part of the problem.
I suggest adding some additional styling in EXTRA.css to fix that:
.xmgCarouselContainer .owl-theme .owl-controls .owl-buttons div