UPS/USPS handoffs seem to vary by location. Out here in SE Arizona, there was a time when UPS began handing off our Amazon pkgs to the local PO. The local carrier would leave a pkg slip and we’d have to go to the PO to retrieve the pkg. It’s a small facility, and you see could thru to back room where their shelves were overflowing with pkgs waiting to be retrieved. But about a year ago UPS stopped using the local PO to deliver their pkgs. We have excellent UPS service out here in rural whiteopia. The local postal employees are outstanding too.
At my work location, I have had a problem with UPS dumping deliveries at the local post office. The local post office does not deliver mail. Everybody in this area has to have a PO Box. So if I indicate a physical address on an order, it ends up going back to the sender.
Now I put the PO Box number and the physical address on orders. That usually works, but not always.