add validation to one more field with a new error message as it is in fact possible to tirgger the validation in the setup section

app/models/validations/sales/household_validations.rb

@@ -24,6 +24,7 @@ module Validations::Sales::HouseholdValidations
     return unless record.form.start_date.year >= 2023
 
     if record.buyers_will_live_in? && record.buyer_one_will_not_live_in_property? && record.buyer_two_will_not_live_in_property?
+      record.errors.add :buylivein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent_setup")
       record.errors.add :buy1livein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
       record.errors.add :buy2livein, I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
     end

config/locales/en.yml

@@ -443,6 +443,7 @@ en:
       postcode:
         discounted_ownership: "Last settled accommodation and discounted ownership property postcodes must match"
       buylivein:
+        buyers_will_live_in_property_values_inconsistent_setup: "You have already told us that both buyer 1 and buyer 2 will not live in the property"
         buyers_will_live_in_property_values_inconsistent: "You have already told us that the buyers will live in the property. Either buyer 1 or buyer 2 must live in the property"
 
     tenancy:

spec/models/validations/sales/household_validations_spec.rb

@@ -238,6 +238,7 @@ RSpec.describe Validations::Sales::HouseholdValidations do
         it "triggers a validation if buyer two will also not live in the property" do
           sales_log.buy2livein = 2
           household_validator.validate_buyers_living_in_property(sales_log)
+          expect(sales_log.errors[:buylivein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent_setup")
           expect(sales_log.errors[:buy2livein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
           expect(sales_log.errors[:buy1livein]).to include I18n.t("validations.household.buylivein.buyers_will_live_in_property_values_inconsistent")
         end