I recently discovered the site I am developing in Magento 2 is missing the Postcode field in the Shipping Address form on the checkout page. I have been digging around and cannot find any reason why it is missing. I found this bug someone opened with Magento but the solution mentioned does not work for me. The results I am seeing are the same though.
On /checkout/
in the Shipping tab the Postcode field is missing. But I am able to continue to the next step. However when I try to complete the checkout I get the error An error occurred on the server. Please try to place the order again.
which I believe is because the address has no zip code. This is while checking out as a guest. I have tested checking out as a customer who already has an address saved and that lets me complete the checkout.
I have disabled all modules and returned to using the Luma theme for testing and I am seeing the same results. Unfortunately upgrading to 2.2 isn't an option at the moment as we are dangerously close to launch so we will have to update after launch. So I don't know if that update will fix this issue or not.
Magento CE 2.1.8
PHP 7.0.24
If anyone has any guidance or suggestions on how to find my missing field I would greatly appreciate it.
EDIT
The Phone number field is missing as well. While that isn't as much of a concern, it is probably missing for the same reason.
Also, I just realized that the data migration from our old site (1.9.3) seems to have caused the issue. I tested our new site with a DB before and after the migration and that is what caused us to lose the postcode field. Our data migration only contains Sales data and Customers - no products or categories. I'm digging in now to see what would have caused it. I have tried a reindex multiple times and that didn't solve it.