Answer
It is important to localize Tyre for a proper postcode search. Localizing Tyre can be done on the ‘Google Maps – Map’ tab from the ‘Preferences’ window: set the ‘Google Maps’ location to your own country. E.g. https://maps.google.co.uk
Google seems to use different databases, because if you search for postcodes on Google’s own website, the proper place is returned. Programmers like me cannot use the Google’s website interface directly. We have to use API functions (if that means anything to you). Using those API functions, another interface and another database is used. I don’t understand why. But that is how it is.