Tia,I work for USPS and the Inspector General is NOT for missing packages, especially International Packages. It will get referred to the local Post Office or the International folks for resolution. The Inspector General is for major financial wrongdoings, like stealing money out of the till.
As others have said above, this whole COVID-19 situation has thrown all transportation out of whack. USPS has had to do six shipments by ship to handle parcels to Europe because there are no flights to put anything on. Most countries are not even accepting mail from other places, including the US. Just in case the parcel was damaged in handling, file a missing mail search at the link I'm going to give you, it's the one at the bottom. https://www.usps.com/help/missing-mail.htm
As for no time stamp on the "in transit" scan, there never is one. I work with this all day every day. Continue working with the folks in Consumer Affairs in Milwaukee. Nothing is the norm right now. Have patience, I know it's hard but due to the sheer amount of parcels in the system right now, things are just bananas.
I really appreciate your input and especially about the time stamp. . I talked to someone in the Milwaukee office yesterday and she believes it will be returned to sender. I was trying to be patient and did not call today. It has been in this "return to sender" state since May 8th. Needs to go from Chicago to Chicago! Will keep the forum posted!