Css Bootstrap 4：下拉菜单在屏幕右侧消失

我似乎不能让下拉项目不从页面上消失.我try 了BS3中的几种方法，但它们似乎都不起作用.我不确定是不是因为ml-auto.(忽略If-Else语句)

以下是CodePen条:

<div class="container-fluid">
  <nav class="navbar fixed-top navbar-toggleable-md navbar-inverse" style="background-color: #3c763d!important;">

    <button class="navbar-toggler navbar-toggler-right navbar-toggler-custom" type="button" data-toggle="collapse" data-target="#searchNav" aria-controls="searchav" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>

    </button>

    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>

    </button>

    <!-- <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarToggleExternalContent" aria-controls="navbarToggleExternalContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
    </button> -->

    <div id="logo">
      <a class="navbar-brand" href="/">Company</a>
    </div>

    <div class="collapse navbar-collapse" id="searchNav">
      <ul class="navbar-nav mx-auto">

        <form action="/search" class="form-inline">
          <input class="form-control mr-sm-2" id="keyword" name="keyword" :value='keyword' type="text" placeholder="Search for jobs" />
          <!-- <div class="input-group"> -->

          <input class="form-control mr-sm-2" id="location" name="location" :value='location' type="text" placeholder="Location" />
          <!-- <button class="btn btn-secondary" type="button">Find Jobs</button> -->
          <!-- </span> -->
          <!-- </div> -->

          <button class="btn btn-secondary my-2 my-sm-0" type="submit">Find Jobs</button>
        </form>

      </ul>
    </div>
    <div class="collapse navbar-collapse" id="navbarNav">

      <ul class="navbar-nav ml-auto">
        <li class="nav-item"><a href="/post" class="nav-link"><strong>Post Job</strong></a></li>

        <div class="hidden-lg-up">

          <li v-if="!user_logged" class="nav-item">
            <a v-if="!user_logged" href="/signup" class="nav-link"><strong>Register</strong></a>
          </li>

          <li v-if="user_logged && user_type === 'user'" class="nav-item">
            <a v-if="user_logged && user_type === 'user'" href="/profile" class="nav-link"><strong>Profile</strong></a>
          </li>

          <li v-if="user_logged && user_type === 'user'" class="nav-item">
            <a v-if="user_logged && user_type === 'user'" href="/applied" class="nav-link"><strong>My Jobs</strong></a>
          </li>

          <li v-if="user_logged && user_type === 'user'" class="nav-item">
            <a v-if="user_logged && user_type === 'user'" href="/searches" class="nav-link"><strong>My Searches</strong></a>
          </li>

          <li v-if="user_logged && user_type === 'company'" class="nav-item">
            <a v-if="user_logged && user_type === 'company'" href="/dashboard" class="nav-link"><strong>Employer Dashboard</strong></a>
          </li>

          <li v-if="!user_logged" class="nav-item">
            <a v-if="!user_logged" href="/login" class="nav-link"><strong>Login</strong></a>
          </li>

          <li v-if="user_logged" class="nav-item">
            <a v-if="user_logged" href="/logout" class="nav-link"><strong>Logout</strong></a>
          </li>
        </div>

        <div class="hidden-md-down">
          <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="/" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
              <strong>Account</strong>
            </a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">

              <!-- <li v-if="!user_logged" class="nav-item"> -->
              <a v-if="!user_logged" href="/signup" class="dropdown-item"><strong>Register</strong></a>
              <!-- </li> -->

              <!-- <li v-if="user_logged && user_type === 'user'" class="nav-item"> -->
              <a v-if="user_logged && user_type === 'user'" href="/profile" class="dropdown-item"><strong>Profile</strong></a>
              <a v-if="user_logged && user_type === 'user'" href="/applied" class="dropdown-item"><strong>My Jobs</strong></a>
              <a v-if="user_logged && user_type === 'user'" href="/searches" class="dropdown-item"><strong>My Searches</strong></a>

              <!-- </li> -->

              <!-- <li v-if="user_logged && user_type === 'company'" class="nav-item"> -->
              <a v-if="user_logged && user_type === 'company'" href="/dashboard" class="dropdown-item"><strong>Employer Dashboard</strong></a>
              <!-- </li> -->

              <!-- <li v-if="!user_logged" class="nav-item"> -->
              <a v-if="!user_logged" href="/login" class="dropdown-item"><strong>Login</strong></a>
              <!-- </li> -->

              <!-- <li v-if="user_logged" class="nav-item"> -->
              <a v-if="user_logged" href="/logout" class="dropdown-item">
                <div class="dropdown-divider"></div>
                <strong>Logout</strong>
              </a>
              <!-- </li> -->
            </div>

          </li>
        </div>

      </ul>
    </div>
  </nav>

</div>