Arrows broken on site

Hello,

This is an amazing plugin, but I found a few things that aren’t working properly. I was wondering if there was css that could fix this.

(see link) When I click the arrows, they tend to jump around not really letting it click to the next image. I tried to move them but it still has this weird affect.

I was hoping you could help me with this, thank you in advance ??

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