Other users are reporting this as well, Alex.
You can enter 00000 in the Postal Code field, so you can save your payment details. You can update it back when this issue will be fixed. That's our workaround at the moment.
We’ve already alerted our engineers about this behavior. The initial target date to resolve this is in mid-November. While waiting for that, please contact our Email team, so they can add your company information to the of affected users. I won't be able to ask it from here since this is a public forum.
Let me know if you have other concerns aside from updating your payment details.