try using before_initialize

Author: ashleywillard

lib/packs/rails/railtie.rb

@@ -5,13 +5,13 @@ module Rails
     class Railtie < ::Rails::Railtie
       config.before_configuration do |app|
         Integrations::Rails.new(app)
-        
+
         # This is not used within packs-rails. Rather, this allows OTHER tools to
         # hook into packs-rails via ActiveSupport hooks.
         ActiveSupport.run_load_hooks(:packs_rails, Packs)
       end
-      
-      config.after_initialize do |app|
+
+      config.before_initialize do |app|
         Integrations::FactoryBot.new(app)
       end
     end