TurboTax is using a single field for both postal codes (not the rest of the address, since they obviously can be different). When you put input anything in the Other Financial Asset postal code it overwrites the first.
Example. I put the word DUMMY in the Other Financial Assets postal code, and it overwrote the Foreign Account postal code. I revisited later and wrote BUG in the Foreign Account postal code and it then showed the same in the Other Financial Assets.
