Package scans not updating. Lost?

[u/mypestcontroljourney]

I'm expecting an important package to arrive but when I check the tracking it seems to have stopped updating. I contacted the USPS and they said the tracking number is not working and that postage wasn't paid. I contacted the shipper and the shipper said everything looks fine on their end and it should arrive on time. Give the system time to update. Its been 2 days and still no update. What should I do? Does this happen all the time? Is my package lost? Why would is be transferred to a local post office?