Contacts in iPhone missing zip codes

I keep my contacts, including complete addresses, in Gmail Contacts and use the Contacts app on my iphone to access them. I have my phone's region set to United States, but am living abroad and using a local SIM. When I look up an address in Contacts, it doesn't show the zip code. This is true even if I entered the address and specified U.S. on the app. I can trick it by clicking edit while in a contact and selection U.S. (again), then the zip will appear. But the next time I come back, it's hidden again. I noticed even when I was in the U.S. using a U.S. SIM card, it still wouldn't show me the zip codes of my U.S. contacts.

Could you please fix this glitch? Many people have contacts in different countries. If I specify a country for a contact, the formatting should reflect that country AND *display* in that same format. Also, it would make sense if the formatting default (if I haven't specified the country) should follow the region set on my phone. Thanks!