DoubleRenderError (Render and/or redirect and adding 'and return' at the end of redirect_to or self.render

I have a messaging system every time I insert a message into the database. it insert duplicates im getting AbstractController::DoubleRenderError (Render and/or redirect were called multiple times in this action). I tried to add and return at the end of redirect_to or self.render but it did not help. the problem it seems to be happening from the create method

# app/controllers/messages_controller.rb

class MessagesController < ApplicationController
   before_action :authenticate_user!
   before_action :set_conversation

  def index
    if current_user == @conversation.sender || current_user == 
      @conversation.recipient
      @other = current_user == @conversation.sender ? 
      @conversation.recipient : @conversation.sender
      @messages = @conversation.messages.order("created_at DESC")
    else
      redirect_to conversations_path, alert: "You don't have permission to view this."
    end
  end

  def create
    @message = @conversation.messages.new(message_params)
    @messages = @conversation.messages.order("created_at DESC")
    if @message.save
      ActionCable.server.broadcast "conversation_#{@conversation.id}", 
      message: render_message(@message)
      redirect_to conversation_messages_path(@conversation)
    end
  end

  private
  def render_message(message)
    self.render(partial: 'messages/message', locals: {message: message})
  end
  def set_conversation
    @conversation = Conversation.find(params[:conversation_id])
  end
  def message_params
    params.require(:message).permit(:context, :user_id)
  end
end

This is an image from my terminal

by removing

      ActionCable.server.broadcast "conversation_#{@conversation.id}", message: render_message(@message)
      redirect_to conversation_messages_path(@conversation)

it still insert duplicates messages

  def create
      @message = @conversation.messages.new(message_params)
      @messages = @conversation.messages.order("created_at DESC")
      @message.save
  end

this image of terminal before removing from the code

This an image from database show that it inserting duplicates

This new image from the terminal after i inserted

this is the view app/views/messages/index.html.erb

<div class="row">
  <div class="col-md-3 text-center">
   <%= image_tag avatar_url(@other), class: "img-circle avatar-medium" %>
   <strong><%= @other.fullname %></strong>
   <%= link_to "View Profile", @other, class: "btn btn-default" %>
 </div>
<div class="col-md-9">
 <div class="panel panel-default">
   <div class="panel-heading">
    Conversation with <%= @other.fullname %>
    <input id="conversation_id" type="hidden" value="<%= 
    @conversation.id %>">
    </div>
    <div class="panel-body">
    <div class="container text-center">
      <%= form_for [@conversation, @conversation.messages.new], remote: true do |f| %>
          <div class="form-group">
            <%= f.text_field :context, placeholder: "Add a personal message", class: "form-control" %>
          </div>
          <%= f.hidden_field :user_id, value: current_user.id %>
          <div>
            <%= f.submit "Send Message", class: "btn btn-normal" %>
          </div>
      <% end %>
    </div>
  </div>
</div>

<div id="chat">
  <%= render @messages %>
</div>