I have looked into this more and so far we have no found an issue, but that does not mean there is not anything.
If you are having an issue with Attendees not showing with WooCommerce Tickets please follow these steps.
Go to WooCommerce->Orders and open one of the ticket orders.
Please check the Order Status, if it is not set to Completed please set it to completed, update the order and then check the attendees list. (you can do a bulk edit on the Ticket Orders and Mark Completed)
If you would like to change the default behavior of WooCommerce to set ticket purchase orders to be marked completed please look at the last post in this topic:
Attendees not showing
This should show the attendees, so I am going to close this ticket. If anyone is still having issues with attendees not showing please create a new support ticket and we will help you out.
Thanks