Cocoon First Option Not Saving - Nested Fields - ruby-on-rails

Question

I'm using Cocoon for a nested form, however the first set of fields do not save into the database, if I create a second row they seem to save just fine?
I'm guessing its just something I'm overlooking
class Form < ActiveRecord::Base
has_many :questions
accepts_nested_attributes_for :questions, :reject_if => :all_blank, :allow_destroy => true
end
class Question < ActiveRecord::Base
belongs_to :form
end
----- form_controller.rb
def new
#form = Form.new
#form.questions.build
end
def create
#form = Form.new(form_params)
if #form.save
redirect_to action: "show", id: #form.id
else
render('new')
end
end
def form_params
params.require(:form).permit(:title, :description, :status, questions_attributes: [:form_id, :question_type, :question_text, :position, :answer_options, :validation_rules, :done, :_destroy])
end
<%= simple_form_for Form.new ,:url => {:action => :create} do |f| %>
<div class="section-row">
<div class="section-cell">
<%= f.label :title, "Form Title" %>
<%= f.text_field :title, placeholder: "Form Title" %>
<br/></br>
<%= f.label :description, "Form Description" %>
<%= f.text_area :description, placeholder: "Form Description" %>
<%= f.hidden_field :status, value: "online" %>
</div>
</div>
<div class="section-row">
<div class="section-cell">
<div id="questions">
<%= simple_fields_for :questions do |question| %>
<%= render 'question_fields', :f => question %>
<%= link_to_add_association 'add question', f, :questions %>
<% end %>
</div>
</div>
</div>
<div class="section-row">
<div class="section-cell">
<%= f.submit "Create Ticket", class: "btn btn-primary btn-lg" %>
</div>
</div>
<% end %>
---- _question_fields.html.erb
<div class='nested-fields'>
<%= f.label :question_type, "Question Type" %>
<%= f.select :question_type,
options_for_select([['Text Box','textbox'],['Dropdown Options','select'], ['Mutiple Choice','radio']], params[:question_type]),
{}, { :class => '' } %>
</div>

Answer 1

You forgot the f in front of the simple_fields_for : then the simple_fields_for has no knowledge of the form, nor the associations, so it will name the parameters posted to the controller differently, so it will be blocked by your strong parameters definition.
So if you write
f.simple_fields_for :questions do |question|
it should just work ;)
Smaller remarks:
the link_to_add_association should be outside of the loop, otherwise it will not be visible if there are none, and will be displayed for each question (which may or may not make sense in your UI).
you should add the id inside the strong parameters for questions_attributes (important for editing/deleting)

Answer 2

You wrote the link_to_add_association inside the simple_fields_for
you should write your form as follows (as documented):
<div id="questions">
<%= f.simple_fields_for :questions do |question| %>
<%= render 'question_fields', f: => question %>
<% end %>
<div class="links">
<%= link_to_add_association 'add task', f, :questions %>
</div>