Carmen-rails how to display the default selected state value?

I've been trying to follow this: Why is carmen-rails not defaulting the saved state and GitHub issue: country_select in nested model doesn't get filled when editing record. But I can't seem to get the code working.

I've added sub_region to pass to the partial but I think the problem is my @country value is nil for some reason when I go to the edit form. When I am selecting the country, my @testcountry.inspect dynamically returns the selected country. When creating a new user, the form works fine. After choosing country, the state field dynamically updates to the relevant select dropdown list.

_subregion_select.html.erb

<div id="order_state_code_wrapper">
  <% parent_region ||= params[:parent_region] %>
  <% sub_region ||= params[:sub_region] %>

  <% @testcountry = Carmen::Country.coded(parent_region) %>

  <% unless parent_region.nil? %>
    <% @country = Carmen::Country.coded(parent_region) %>
  <% end%>

  <%= @testcountry.inspect %>

  <% if @country.nil? %>
    <em>Please select a country above</em>
  <% elsif @country.subregions? %>
    <%= subregion_select(:user, :subdivision, parent_region) %>
  <% else %>
    <%= text_field(:user, :subdivision) %>
  <% end %>
</div>

_form.html.erb

<%= form_for(@user) do |f| %>
  <div class="field">
    <%= f.label :country %><br />
    <%= f.country_select :country, priority: %w(US CA), prompt: 'Please select a country' %>
  </div>

  <div class="field">
    <%= f.label :subdivision, "State/Province" %><br />
    <%= render 'subregion_select', locals: {parent_region: f.object.country, :sub_region => f.object.subdivision } %>
  </div>

  <div class="field">
    <%= f.label :city %><br>
    <%= f.text_field :city %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

users.js.coffee

$(document).on 'ready page:load', ->
  $('select#user_country').change (event) ->
    select_wrapper = $('#order_state_code_wrapper')

    $('select', select_wrapper).attr('disabled', true)

    country = $(this).val()

    url = "/subregion_options?parent_region=#{country}"
    select_wrapper.load(url)

users_controller.rb

def subregion_options
  render partial: 'subregion_select', locals: { parent_region: params[:parent_region], sub_region: params[:sub_region] }
end

Any insight would help, thank you!