Ошибка: двойные вложенные формы в активном админке с habtm

ActionView::Template::Error (undefined method `events' for # Did you mean? eventusers):

1: insert_tag renderer_for(:new)

app/admin/programs.rb:23:in block (5 levels) in <top (required)>' app/admin/programs.rb:22:inblock (4 levels) in ' app/admin/programs.rb:21:in block (3 levels) in <top (required)>' app/admin/programs.rb:17:inblock (2 levels) in '

Doubled nested forms Programs -> events -> eventusers joint tables : events_programs and events_eventusers

модели:

class Program < ApplicationRecord
  has_and_belongs_to_many :events, join_table: 'events_programs'
  accepts_nested_attributes_for :events, allow_destroy: true
end

class Event < ApplicationRecord
  has_and_belongs_to_many :programs
  has_and_belongs_to_many :eventusers, join_table: 'events_eventusers'
       accepts_nested_attributes_for :eventusers, :allow_destroy => true
end

class Eventuser < ApplicationRecord
  has_and_belongs_to_many :events
end

админ / programs.rb

ActiveAdmin.register Program do


permit_params :name, events_attributes: [:id, :name, :_destroy, eventuser_ids: []]#s_attributes: [:id, :name, :role, :_destroy]]


form do |f|
    f.semantic_errors *f.object.errors.keys
    f.inputs do
        f.input :name


        f.inputs do
            f.has_many :events, allow_destroy: true do |a|
                a.input :events, as: :select, collection: Event.all.uniq.map{|e| e.name} #, :input_html => { :class => 'chosen-select' }
                a.inputs "users" do
                    a.has_many :eventusers do |a|
                        a.input :eventuser_ids, :as => :select, collection: Eventuser.all#.uniq.map{|e| [e.name, e.role]} , :input_html => { :class => 'chosen-select' }
                    end
                end
            end
        end
    end
    f.actions
end


end