Issue with clunky slideshow animations and images hanging during transition

I have a customized SS site and am having issues getting the images to transition smoothly within my galleries. I would also be fine with there being no animation if that is a more feasible fix. The last/previous image in the gallery seems to get hung up when transitioning to the next before abruptly disappearing. This unfortunately makes the slideshow experience feel quite clunky.

My website url is www.ransomashley.com

The developer I worked with on my site didn't know how to solve this so I wondered if any of you had similar issues and/or could offer any insight.

Hi, did you ever find a solution to this issue? Having the exact same problem when using a random gallery order plugin on my homepage.

Hope you've had better luck than I have!