The plugin is as simple as can be. I select SITE A and then select a number of posts, then select destination SITE B and copy. I always receive the "success" message.
But half of the time, no posts are copied! Some of the time, one post is copied! On one occasion, 3 posts were copied.
I have tried doing one at a time, 5 and even bulk. No pattern. The account I am using has full admin rights to each site AND is a super admin.