当作为Wordpress主题运行时，Bootstrap导航栏不会折叠

Question

我有一个使用Bootstrap和折叠导航栏的静态HTML网站，但是当我拆分它以将其变成Wordpress主题时，设计很好，唯一不能正常工作的是导航栏。移动视口。导航栏将打开以显示链接但它不会再次折叠，并且它会被打开。

将header.php中的代码放入普通的HTML文件中会使导航栏变好。

的header.php

<meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <!-- Bootstrap + dependencies -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

    <!-- style -->
    <link href="<?php echo get_bloginfo('template_directory'); ?>/style.css" rel="stylesheet">


    <!-- Image and text -->
    <nav class="navbar navbar-expand-lg navbar-light bg-light">
      <a class="navbar-brand" href="#">Navbar</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavAltMarkup" aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarNavAltMarkup">
        <div class="navbar-nav">
          <a class="nav-item nav-link active" href="#">Home <span class="sr-only">(current)</span></a>
          <a class="nav-item nav-link" href="#">Features</a>
          <a class="nav-item nav-link" href="#">Pricing</a>
          <a class="nav-item nav-link disabled" href="#">Disabled</a>
        </div>
      </div>
    </nav>