I don't think I've had anything lost coming from China.
But, I usually budget about a month for shipping. There are often some odd pauses in the movement.
One thing about post office scanning. They may either scan your package, or put your package into a container, and scan that container as representing everything that is supposed to be inside.
This may well also apply to ports. So if a 40 foot conex box arrives, they may simply scan the manifest with that box, but it could take a few days to empty it.