Have you checked all around your property as well as asking your neighbours. Some couriers will leave in all kinds of places.
If you still can not find it then your problem is between yourself and the courier or Rm whoever said they delivered.
You need to contact them and ask where the item is.
If you open a I have not received my item dispute then you would lose if the tracking says Delivered.
Are you sure you have the corrected delivery address on your items?.
Ebay will always give the addresss you have onsite.
https://www.ebay.co.uk/help/account/changing-account-settings/changing-address-ebay-account?id=4201
_____________________
We are just ordinary members trying to help.