Lightbox problem on Safari last release

[Chris]

Hi Harmin,
first of all congrats for your job, lay theme is really nice!
I have noticed a bug regarding the lightbox addon on a website I recently created (giuseppemarano.com). It happens on Safari 11.0.2 running on macOS Sierra 10.12.6.
When you slide from an image to the next, there's a little vertical movement of the image (something like a rebound while the images are sliding horizontally).
Do you have a solution for this?

Thanks in advance.

Chris