There are 6 address areas to check - the registered one in Personal Information and another 5 in the Addresses section.
Go to your My eBay>Account, here:
https://accountsettings.ebay.co.uk/uas?_trksid=p2060353.m2034.l3911
In the first section, "Personal information and privacy" you'll see 'Personal Information' - you can change your registered address there.
Then go to 'Addresses' and update the addresses in that section too.