USPS Tracking Says “Invalid Number” but Package Still in Transit

I shipped my package on the 6th, but it still has not arrived. When I check the tracking system, it says “your order number is incorrect” or “status will be updated,” but nothing actually changes or gets updated.
When I check through another tracking system, it shows that my package is still in transit. USPS says that the courier has been notified and will pick it up, but there has been no delivery or clear update so far.
I would like to know why this is happening and when my package will finally be delivered.


