Hello,
In PHP 5.6 is giving problems, set up to version 5.5 and it worked normally.
But I found the problem, the plugin makes a query_attachments request to admin-ajax.php informing the draft ID instead of WordPress return empty it returns all images. I checked the file wp-admin / includes / ajax-actions.php on line 2363 “$ query = array_intersect_key ($ query, array_flip ($ keys))”, PHP 5.6 does not include the post__in for some reason, and just returning all images.
I do not know if it’s correct, but I think it could verify that it is indeed necessary to request the images when the post is still in draft.