Slide by single item not displaying correctly

Hoping someone can help point me in the right direction here.
I’ve set up my slider to only show a single slide per page but for some reason the second slide is overlaying the first – as you will see in the link.

When you resize the screen it seems to sort itself out but on first load it’s overlapping.

Can anyone help?

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