Amazon has an alert posted on Seller Central warning sellers of posting delays of orders. It advised sellers not to cancel orders and promised to protect their performance standards.
The terse warning provided no further details.
Subject: Technical Notification: MFN Order Posting delays
Update 03/02 – 17:32 PDT)
Please fulfill orders once you are able, rather than cancelling. For all orders impacted, we will reverse late shipment defects and we will take additional steps as needed to mitigate any impact to your account health. At this time, there are no actions you need to take.
We are currently experiencing an issue that is delaying the posting of recently placed orders in Manage Your Orders. Engineers are actively looking into this issue. (03/02 – 15:00 PDT).