Is this with WiFi on or off? What devices?
Since the phenomenon appears to be based on IP address, I would expect the same outcome on all devices that share the broadband connection via NAT, both wired and WiFi. This is borne out by observations...
Tablets, phones and PCs all show the same... Great Yarmouth, including a laptop belonging to a visitor, but connected as a guest to our network. Some of these devices, such as tablets and phones are, obviously, connected via WiFi. My desktop PC however has a wired connection but gives the same result... I am hundreds of miles away, in Great Yarmouth.
On phone if I disable WiFi, so it falls back to mobile data, google search unsurprisingly bases its results on a different IP and shows a different location - “Greater London”. Still wrong, but not as daft as Great Yarmouth.