The reason may be that merchants submit logistics information on Taobao, but it is not worthy to be sent to logistics companies;
Or the merchant has an error in filling in the logistics information;
Or the goods received by the logistics company were not scanned in time.
Extended data:
If the seller does send it, but there is still no logistics, it may be that the logistics update of the website is too card and the logistics dynamics are not obtained. I have encountered this situation. However, in this case, you can copy the courier number, enter the name of the corresponding courier company on Baidu's homepage, and then search.
If not, it means there is no logistics information (if Baidu finds logistics here, it means the background is stuck), as shown in the figure, it means there is no logistics. It is possible that the courier may still be in the sending company, because once it is shipped away, it at least means that the courier has been received.