A "Not Found" status can result from several issues. To address them, consider the following solutions:
1. Incorrect Tracking Number:
Verify the tracking number and re-register if necessary.
2. Incorrect Carrier:
Check the carrier assigned to the shipment. If incorrect, update the carrier as needed: How to fix an incorrect carrier registration?
3. Carrier API Issue:
Wait for the next tracking update if there is a problem with the carrier's API.
4. Carrier Hasn't Updated Tracking Data:
The tracking information may not yet be available; please wait until the carrier updates it.
5. Missing Tracking Parameters:
Ensure all required tracking parameters are included and complete any missing ones if necessary.