Make sure you have changed the correct address on eBay, there are 5 for you to amend here with the link below, , and use a laptop / PC for this not the app or mobile browser.
Just editing to add, at eBay checkout to make sure you have the correct delivery address before paying, going left and check the delivery address there. That is where your item will be sent to, if it's wrong you can correct it there.
https://accountsettings.ebay.co.uk/uas/addresses
@ndu_2930