i'm sure this is resolved by now, but the way it works is that one item gets moved over immediately, and the rest are queued and get processed later. so if you're moving a page of items, 100 items (one of each) will be put into the new shop immediately, and the rest go into a queue to get added over time.

if you're missing any after getting all of your queue events (you'll get one for each page/batch you send), file a ticket. :)