Right now there is an issue with creating shipping labels and confirming orders (about 5% of all requests end up in a failure/time-out)
Please check your process status
Retrying your request can result in a succesful request
Update 13:55 : The issue seems to be bigger; also GET orders is affected. The reponses can be incomplete. Items can be missing
Update 14:30 : The issue is resolved. Please check the list of open orders for new order items