I had a similar case earlier this year. My CGC return shipment package was scanned into the Tampa, FL USPS regional facility and there was no futher movement for two weeks. I filed a lost package claim through the USPS website myself and within a week the package started moving through the system again and made it to my home in Omaha a week later. The claim was for $1200 the FMV of all the books in the shipment. I never found out what happened but my suspicion is the registered mail package