Gem railsconfig/config not loading when bundled into an app via mountable rails engine

Question

I am writing a rails 5.2 mountable engine for configuring a rails application as part of an service oriented architechture.

I have been trying to use the Config Gem inside of the engine and I keep getting the following error

install_generator.rb:28:in 'create_database_yml': undefined method 'adapter' for nil:NilClass (NoMethodError)

This is is because I am trying to build a generator that makes a properly configured database.yml file based on values interpolated via the Config gem into a string that gets copied into the file. The method causing the error is below and that full generator module code is in a gist below as well.

generator.rb

    def create_database_yml
         database_name = Rails.application.class.parent_name.underscore.gsub("_","-")
        create_file('config/database.yml',
          %{default: &default
  adapter: 'Settings.database.adapter'
  encoding: unicode
  pool: <%= ENV['RAILS_MAX_THREADS'] || 5 %>
  prepared_statements: false

development:
  <<: *default
  database: #{database_name}_dev

production:
  <<: *default
          }
        )
      end

I have bundled the gem into a rails project and when I run the generator this is when I get the error that I mentioned above.

You can see a full stack trace below.

When I open a rails console and I call the Settings, object

...( which is an alias for the Config object that is the core of the gem. )

I get a valid Settings object returned in the console. This lets me know that the Settings object IS available in the rails app that runs my engine.

However the error leads me to believe that the call to Settings returns a valid object... then the call to .database returns nil. And then we get that famous rails error undefined method for nil:NilClass

my settings.yml file for the gem is properly formatted so theres no reason that this syntax wont work as I use the gem in almost every project so Im well aware of its features and how to use it.

database:
  adapter: 'postgresql'

This only leads me to believe that for some reason the settings gem is not loading the .yml files as it should. Maybe the load paths are getting messed up, or maybe the config gem is loading at the wrong time when the engine is bundled into an app.

Anybody who has any info on how to get this gem properly working in an engine would be greatly appreciated.

this is a gist of the full stack trace

full stack trace to error