Does not include scan data. When the courier company has not received this single courier, or has not had time to enter information after receiving it, it can't find the relevant logistics information. It is also possible that the seller (shipper) clicks on the delivery and uploads the single number, but there is no delivery.
Information error. The shipper sent the wrong order number or wrote the wrong courier company.
The sender did not send it. After the shipper sent the express mail, the package picker didn't send it to you for some reason (such as losing it, forgetting to hand it in, and putting it in a corner of the warehouse).
Express delivery does not scan. It was the shipper who gave the express mail to the courier, but the courier didn't scan it for some reasons, such as too many pieces that needed to be scanned in batches, or the delivery failed to be loaded on the day of receipt, or the list was torn and replaced with a new single number.
The courier is lost. Maybe it was too small, so it was lost before it was sent out.
Extended data:
Solutions to the above situation:
You should contact the seller in time, ask the specific reason and let it handle it.
Contact the courier salesman, ask the courier number and make an inquiry.