Bootstrap 下拉菜单在点击时不适用于移动设备

Question

我在我的网站上添加了一个下拉菜单，但当导航栏折叠时，它在移动设备上无法正常工作。当我单击下拉菜单时，它会关闭导航栏而不是显示下拉菜单下的项目。.dropdown-submenu {  position: relative;}.dropdown-submenu .dropdown-menu {  top: 0;  left: 100%;  margin-top: -1px;}<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/jquery.min.js"></script><script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script><link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css"><nav class="navbar navbar-default navbar-fixed-top">    <div class="container">        <!-- Brand and toggle get grouped for better mobile display -->        <div class="navbar-header page-scroll">            <button type="button" class="navbar-toggle" data-toggle="collapse"                    data-target="#bs-example-navbar-collapse-1">                <span class="sr-only">Toggle navigation</span>                <span class="icon-bar"></span>                <span class="icon-bar"></span>                <span class="icon-bar"></span>            </button>            <a class="navbar-brand" href="#page-top">Name</a>        </div>        <!-- Collect the nav links, forms, and other content for toggling -->        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">            <ul class="nav navbar-nav navbar-right">                <li class="hidden">                    <a href="#page-top"></a>                </li>                <li class="page-scroll">                    <a href="#portfolio">Portfolio</a>