Not sure as I don't use a EU map.
AFAIK for multi country maps you must select the country too.
I assume you did that or your already tried to other addresses in the UK.
How exactly to you enter this address?
If there are two town with the same name in different countries, by default the one in the country of your current location should be highlighted.
Is it possible that Swindon UK is displayed right under Swindon DE?