リッチテキストが保存されない

Question

###環境
OS:Ubuntu server 20.04STL
Ruby:2.7.2
Rails:6.0.3.4

###状況
このブログを参考にリッチテキストを作成したところ、postしたものが表示されませんでした。postはできて、showで見れない感じです。titleは表示されます。よろしくお願いします。

###コンソールログ

rails new blog
cd blog
bundle install
bundle exec rails action_text:install
bundle exec rails g scaffold post title:string
bundle exec rails db:create
bundle exec rails db:migrate
rails s


Rendered posts/show.html.erb within layouts/applicationEverything's up-to-date. Nothing to doStarted GET "/posts/7/edit" for 192.168.0.7 at 2020-11-16 18:49:05 +0900
Cannot render console from 192.168.0.7! Allowed networks: 127.0.0.0/127.255.255.255, ::1
Processing by PostsController#edit as HTML
  Parameters: {"id"=>"7"}
  Post Load (0.2ms)  SELECT "posts".* FROM "posts" WHERE "posts"."id" = ? LIMIT ?  [["id", 7], ["LIMIT", 1]]
  ? app/controllers/posts_controller.rb:72:in `set_post'
  Rendering posts/edit.html.erb within layouts/application
  ActionText::RichText Load (0.1ms)  SELECT "action_text_rich_texts".* FROM "action_text_rich_texts" WHERE "action_text_rich_texts"."record_id" = ? AND "action_text_rich_texts"."record_type" = ? AND "action_text_rich_texts"."name" = ? LIMIT ?  [["record_id", 7], ["record_type", "Post"], ["name", "body"], ["LIMIT", 1]]
  ? app/views/posts/_form.html.erb:18
  Rendered posts/_form.html.erb (Duration: 7.1ms | Allocations: 2367)
  Rendered posts/edit.html.erb within layouts/application (Duration: 8.6ms | Allocations: 2739)
[Webpacker] Everything's up-to-date. Nothing to do
Completed 200 OK in 22ms (Views: 18.0ms | ActiveRecord: 0.3ms | Allocations: 7289)

###コード
#####blog/app/models/post

class Post < ApplicationRecord
	has_rich_text :body
end

#####blog/app/controllers/posts_controller.rb

class PostsController < ApplicationController
  before_action :set_post, only: [:show, :edit, :update, :destroy]

   def post_params
   params.require(:post).permit(:title, :body)
   end


  # GET /posts
  # GET /posts.json
  def index
    @posts = Post.all
  end

  # GET /posts/1
  # GET /posts/1.json
  def show
  end

  # GET /posts/new
  def new
    @post = Post.new
  end

  # GET /posts/1/edit
  def edit
  end

  # POST /posts
  # POST /posts.json
  def create
    @post = Post.new(post_params)

    respond_to do |format|
      if @post.save
        format.html { redirect_to @post, notice: 'Post was successfully created.' }
        format.json { render :show, status: :created, location: @post }
      else
        format.html { render :new }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /posts/1
  # PATCH/PUT /posts/1.json
  def update
    respond_to do |format|
      if @post.update(post_params)
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { render :show, status: :ok, location: @post }
      else
        format.html { render :edit }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /posts/1
  # DELETE /posts/1.json
  def destroy
    @post.destroy
    respond_to do |format|
      format.html { redirect_to posts_url, notice: 'Post was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_post
      @post = Post.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def post_params
      params.require(:post).permit(:title)
    end
end

#####blog/app/views/posts/_form.html.erb

<%= form_with(model: post, local: true) do |form| %>
  <% if post.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(post.errors.count, "error") %> prohibited this post from being saved:</h2>

      <ul>
        <% post.errors.full_messages.each do |message| %>
          <li><%= message %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= form.label :title %>
    <%= form.text_field :title %>
    <%= form.label :body %>
    <%= form.rich_text_area :body %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>

#####blog/app/views/posts/show.html.erb

<p id="notice"><%= notice %></p>

<p>
  <strong>Title:</strong>
  <%= @post.title %>
</p>

<%= @post.body %>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>