checkout error- zip code (middle east)

hi there,

a customer wrote to me saying that on checkout (with credit card) she keeps getting error messages regarding zip code for her abu dhabi address (i’m guessing billing address) and couldn’t get through. this was as much info the customer gave me (hence not sure what error msg received). however, in my dashboard, her order had gone through.

is this a bug, why is the client receiving these error messages although the order process did go through?

thank you