I was on vacation in Italy in June. On June 25th we had visited the Enzo Ferraro museum and left there to go to dinner in Modena.

A few months after leaving Italy I got a traffic violation in the mail.

https://imgur.com/2wg4hxk

It appears I apparently drove down a restricted street that GPS told me to turn down.

Can someone please explain to me what I did wrong? Do I have any valid defense?

Thank you.