Country selection gets reset on (regular) checkout address change form if there is an error in form data

[webotron]

I have stumbled across a bug. I was testing the regular checkout process and tried the address change in shipping / payments steps. I have filled in the form and have entered postcode and state only 1 symbol. After submitting the form, I got the expected errors about the wrong length of above mentioned fields, but country selection got reset to the default one.
I have checked my other test site with ZC without bootstrap, and there the field does not get reset.

I am using ZC 2.1.0 beta-1 and bootstrap template 3.7.4

To make it clear, I am talking about forms in these pages:
index.php?main_page=checkout_shipping_address
index.php?main_page=checkout_payment_address