No change, 510 and 931 are also area codes where this happens, but its formatted as 931 or 510 7775555
The only thing is that it has to be a new message from a different address like going from email to the phone number or vice versa
This did not happen in America when i would iMessage from my mac using email and then go back to my phone number, and the iOS version was the same too.
Apple senior rep doesn't know...
Any advice would be appreciated, I have this phone for 4 months and friends back home who like to keep up with my travels.