Rails 5.2 ActiveAdmin deep nested objects - ruby-on-rails

Question

I have this scheme: Course->Segments->Questions.
Course has many segments and segments has many questions.
I added segment_type attribute to segment model so I can show/hide question model depends on the type (video or quiz).
I managed to write the form in courses.rb and I got access to questions through course.
I'm having a problem with showing question attributes in show page even when I searched 3-4 hours on google for answer. Here is a screenshot of the show page
I wrote accept_nested_attribute in all the models so this is not the problem. I can edit, create and delete courses, segments and questions, it's just I can't see in the show the data relevant to questions.
EDIT: I know that the relations works fine in rails console and I have data in questions (it suppose to display the last segment's questions)
these are my models:
class Course < ApplicationRecord
validates :title ,presence: true
validates :author ,presence: true
has_many :segments, inverse_of: :course, :dependent => :destroy, :autosave => true
accepts_nested_attributes_for :segments, :allow_destroy => true
end
class Segment < ApplicationRecord
validates :course_id ,presence: true
validates :data ,presence: true, if: :segment_is_video?
validates :segment_type ,presence: true
validates_presence_of :course
belongs_to :course
has_many :questions, inverse_of: :segments, :dependent => :destroy, :autosave => true
accepts_nested_attributes_for :questions, :allow_destroy => true
def self.segment_type
{"Video": "Video", "Quiz": "Quiz"}
end
def segment_is_video?
segment_type == 'Video'
end
end
class Question < ApplicationRecord
validates :question ,presence: true
validates :answer1 ,presence: true
validates :answer2 ,presence: true
validates :answer3 ,presence: true
validates :answer4 ,presence: true
validates :correct ,presence: true
validates_presence_of :segment
belongs_to :segment
end
this is courses.rb:
ActiveAdmin.register Course do
permit_params :id, :title, :autor,
segments_attributes: [:id, :unit_id, :unit_title, :name, :segment_type, :data, :_destroy, :_create, :_update, questions_attributes: [:id, :question, :answer1, :answer2, :answer3, :answer4, :correct, :_destroy, :_create, :_update]]
config.sort_order = 'id_asc'
member_action :segments do
#segments = resource.segments
end
index do
column :id
column :title
column :author
actions
end
show do
panel "Course Segments" do
h3 "Videos"
table_for resource.segments.where('segment_type = "Video"') do
column :id
column :name
column :data
end
# Here it's only displaying id and name values, but the others no.
h3 "Quizes"
table_for resource.segments.where('segment_type = "Quiz"') do
column :id
column :name
column :question
column :answer1
column :answer2
column :answer3
column :answer4
column :correct
end
end
active_admin_comments
end
sidebar "Course Details", only: :show do
attributes_table_for course do
row :title
row :author
end
end
form do |f|
tabs do
tab 'Basic Info' do
f.inputs "Course details" do
f.input :title
f.input :author
end
end
tab 'Content' do
f.inputs "Segments" do
f.has_many :segments, heading: false, allow_destroy: true do |s|
s.input :unit_id
s.input :unit_title
s.input :name
s.input :segment_type, as: :select, collection: Segment.segment_type, input_html: { class: 'select-type' }
s.input :data, label: 'Url', :as => :string, input_html: { class: 'video-tab' }
s.has_many :questions, heading: false, allow_destroy: true do |q|
q.input :question, input_html: { class: 'quiz-tab' }
q.input :answer1, input_html: { class: 'quiz-tab' }
q.input :answer2, input_html: { class: 'quiz-tab' }
q.input :answer3, input_html: { class: 'quiz-tab' }
q.input :answer4, input_html: { class: 'quiz-tab' }
q.input :correct, input_html: { class: 'quiz-tab' }, as: :select, collection: [1,2,3,4]
end
end
end
end
end
f.actions
end
end