dry-validation nested config inside rules not working

nested_config_not_working.rb

InnerSchema = Dry::Validation.Schema do
  configure do
    option :letter_array
  end

  required(:letter).filled(:str?)

  validate(letter_in_array: :letter) do |letter|
    letter_array.include?(letter)
  end
end

RSpec::describe 'InnerSchema' do
  it('should pass with a know letter') do
    expect(InnerSchema.with(letter_array: ['a'])
    .call( { :letter => 'a' } ).success?).to be true
  end
end

OuterSchema = Dry::Validation.Schema do
  required(:container) { hash? }

  rule(is_inside_letter_known: [:container]) do |container|
    container.schema(InnerSchema.with(letter_array: ['b']))
  end
end

RSpec::describe 'OuterSchema' do
  it('should pass with a nested know letter') do
    expect(OuterSchema.call( { :container => { :letter => 'b' } }).success?)
      .to be true
  end
end

require 'dry-validation'

InnerSchema = Dry::Validation.Schema do
  configure do
    option :letter_array
  end

  validate(letter_in_array: :letter) do |letter|
    letter_array.include?(letter)
  end
end

OuterSchema = Dry::Validation.Schema do
  required(:container) { hash? }

  rule(is_inside_letter_known: [:container]) do |container|
    ls = InnerSchema.with(letter_array: ['b'])
    container.schema(ls)
  end
end

RSpec::describe 'InnerSchema' do
  it('should pass with a know letter') do
    expect(InnerSchema.with(letter_array: ['a'])
    .call( { :letter => 'a' } ).success?).to be true
  end
end

RSpec::describe 'OuterSchema' do
  it('should pass with a nested know letter') do
    # binding.pry
    result = OuterSchema.call container: { :letter => 'b' }
    expect(result.success?)
      .to be true
  end
end