rails bootstrap4の実装において、devtoolsで$$$1.fn.emulateTransitionEnd = transitionEndEmulator;で処理が止まる

Question

RoRでポートフォリオを作成中。
bootstrapを導入し、フロント部分を調整したいと思っております。
その際にブラウザのdevtoolsのnetworkを確認すると画像の通りとなっております

$$$1.fn.emulateTransitionEnd = transitionEndEmulator;で検索をかけるとbootstrapの導入に係るものだと判明しました。
その後に、様々なサイトを参考にしコード等を修正するも、当該エラーが解決しないことから質問させていただきます。
（解決しなかったことから、修正を加える前のデータに戻しております。）

rails 5.2.4.4
ruby 2.6.2

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.6.3'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.2.4', '>= 5.2.4.3'

gem 'bcrypt'
# Use mysql as the database for Active Record
gem 'mysql2', '>= 0.4.4', '< 0.6.0'
# Use Puma as the app server
gem 'puma', '~> 3.11'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'mini_racer', platforms: :ruby

# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 4.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use ActiveStorage variant
# gem 'mini_magick', '~> 4.8'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.1.0', require: false

gem 'bootstrap', '~> 4.1.1'
gem 'jquery-rails'

gem 'faker'

gem 'carrierwave'
gem 'rmagick'

gem 'unicorn'

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  gem 'rspec-rails', '~> 3.7'
  gem 'rails-controller-testing'
  gem 'factory_bot_rails', '~> 4.11'
  gem "pry-rails"
  gem "pry-byebug"
  gem "database_cleaner"
end

group :development do
  # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
  gem 'web-console', '>= 3.3.0'

  gem 'listen', '>= 3.0.5', '< 3.2'
  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'

  gem 'spring-watcher-listen', '~> 2.0.0'
  gem 'spring-commands-rspec'
end

group :test do
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '>= 2.15'
  gem 'selenium-webdriver'
  # Easy installation and use of chromedriver to run system tests with Chrome
  # gem 'chromedriver-helper'

  gem 'webdrivers'
end

gem 'devise'

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

group :development, :staging do
  gem 'rubocop', '~> 0.82.0', require: false
end

group :production do
  gem 'puma_worker_killer'
end

// This is a manifest file that'll be compiled into application.js, which will include all the files
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, or any plugin's
// vendor/assets/javascripts directory can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// compiled file. JavaScript code in this file should be added after the last require_* statement.
//
// Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
// about supported directives.
//
//= require jquery3
//= require popper
//= require bootstrap-sprockets

//= require rails-ujs
//= require activestorage
//= require turbolinks
//= require_tree .

/*
 * This is a manifest file that'll be compiled into application.css, which will include all the files
 * listed below.
 *
 * Any CSS and SCSS file within this directory, lib/assets/stylesheets, or any plugin's
 * vendor/assets/stylesheets directory can be referenced here using a relative path.
 *
 * You're free to add application-wide styles to this file and they'll appear at the bottom of the
 * compiled file so the styles you add here take precedence over styles defined in any other CSS/SCSS
 * files in this directory. Styles in this file should be added after the last require_* statement.
 * It is generally better to create a new file per style scope.
 *
 */
@import "bootstrap";

<!DOCTYPE html>
<html>
  <head>
    <title><%= full_title(yield(:title)) %></title>
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>

    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
    <%= render 'layouts/shim'%>
  </head>

  <body>
    <%= render 'layouts/header' %>
    <div class="container">
      <% flash.each do |message_type, message| %>
        <%= content_tag(:div, message, class: "alert alert-#{message_type}") %>
      <% end %>
      <%= yield %>
      <%= render 'layouts/footer' %>
      <%= debug(params) if Rails.env.development? %>
    </div>
  </body>
</html>

その他、必要なデータがございましたら、その都度対応させていただきます。
また、そもそもの問題定義が間違っている場合は、ご指摘いただければと思います。

追記

 @import "bootstrap-sprockets";
 @import "bootstrap";

//= require jquery3
//= require popper
//= require bootstrap-sprockets
//= require bootstrap <-追加

//= require rails-ujs
//= require activestorage
//= require turbolinks
//= require_tree .

上記の通り修正してみるもSass::SyntaxError inとなる
うまくbootstrapがimportできないようです。
さらに、下記の通りに修正してみる

@import "bootstrap";

//= require jquery3
//= require popper
//= require bootstrap

//= require rails-ujs
//= require activestorage
//= require turbolinks
//= require_tree .

このように修正した結果、エラー等は発生しなくなりました。
しかし、sprocketsを外したことによる影響範囲等を把握できていないこと及びこの修正が正しいのか不明です。