When the Address Block is included as a required field on a User Login part, when filling out a New User Registration, all of the associated address fields appear as required except for Country. In addition, this field can be left blank by the user, and the form will successfully complete the registration.
We are currently evaluating this issue and will update this article when we have more information.
Steps to Duplicate
Create a User Login part.
While configuring it, include Address Block as a required field.
When completing a new user registration, notice that Country does not have a red asterisk beside it.
Set the County to [ blank ] and submit the New User Registration transaction.