Ten years ago I ordered something from eBay with the seller not clear what service he was using to ship the item. I tried contacting him but he still didn't sound very clear.
Here's the issue: I use a post office box. I do not have a street-address mailbox of any kind. Back then, if you sent something to my street address via postal mail, it would often just get lost because you don't typically go to the post office, "Excuse me, have I received any mail lately that you never delivered to me?" After a few years, finally they made a connection between the box and address so that street mail gets the PO Box number written on it and stuffed in the slot.
Asking for it to be sent to my PO Box, not knowing it was being sent UPS or FedEx and you have an entirely new ball of fun waiting for you. First, UPS (or FedEx, whichever it was) never even checked the address at the start to see "Oh, it's a PO Box... maybe we should do some checking first." According to my tracking info, the package went through 3 stops, arrived at the post office building, noted during the delivery it was a PO Box and searched for an alternate address. Sent the package two stops to my old address 250 miles away. The house was still for sale, so that address is obviously no good. They did another search and located the wrong person with my name (in fairness, at least he lives in the same state) who apparently, seeing the wrong address, gave it back to them. They sent it all of the way back to the original location -- three more stops -- and then finally to my doorstep after another few steps. It took 5 weeks.