I have performed two imports using the WP Importer plugin, one of a custom post type and the 2nd of the Media Library. Both imports appear to work, on fact a second attempt to import the Media Library gives "File Exists" messages.

In the individual post the featured image is showing, with thumbnail, with the correct, updated URL. In cPanel, all the images are in place with correct folder structure and thumbnails

But in the media library, there is nothing showing.