Former UPS driver manager here.
1) The trucks don't usually ping in real time. You are typically viewing 5-10 min behind where they actually are.
2) Your package is probably buried somewhere in the back of the truck. The front and floor is typically reserved for businesses or major apartment complexes. As packages get delivered throughout the day space on the shelves open up and the mess at the back of the shelf gets sorted out. If you approach a driver and ask him to dig through his truck to find your package he'll probably tell you to fuck off and you will get your package later that day. He has businesses he's actually has commit windows to meet.
