Hi, sorry for delay...
What I did was to follow this link:
and the comment of mysho.
the file I edited was: root/translations/cldr/main--it-IT--currencies (for you can be en-US or an other one)
for Euro you have to replace "symbol":"\u20ac" with "symbol":"EUR",
for GBP you have to replace "symbol":"\u00a3" with "symbol":"GBP",
etc...
then, of course, clean the cache and it should works.
You can have a look on my website: dailyshopbay
On my own, I add the currency at the end but on the Google webmasters tools, I only highlight the price without the currency and it maybe works!!