Cloner - Copied Media Files Won't Display

I have a weird issue with the WordPress Media Library after using Cloner to clone a site. As you can see from the screenshot I have attached, most images in the library do not show up for the copy of the site.

However, checking the server, I've found that all the images were indeed copied and in the right folder (/wp-content/uploads/sites/2/).

Any ideas as to why this happened and, is there an easy fix? Thanks!