Plugin is Broken

I have sent this issue as a pre-sales question and I was told they will not help until after I purchase.

The plugin correctly changes the byline to multi-author and adds both Author boxes to the post. But it does not register the post to both Authors, only the first one.

When I use the WP Dashboard to see all posts published by author id, the post only shows up under the first Author, not the second.

https://XXXX.wpengine.com/wp-admin/edit.php?author=??

This needs to be fixed.