After filing a new U.S. or PCT patent application (in the U.S.), the USPTO may take several days before it properly populates all the information in Patent Center. This applies to XML files and the "Update Matter" button on a matter details page. If any matter data (such as the filing date) is missing, or any task is failing to generate, try re-downloading the XML file or clicking Update Matter a few days later.

This applied to EspaceNet as well, which must retrieve it's information from the USPTO.