MDB顶部只有一个导航栏

Question

我有两个导航栏，我想在滚动时将两个导航栏粘贴在顶部。使用我的代码，只有一个导航栏停留在顶部。请在下面查看我的代码：

这是第一次导航

<mdb-navbar SideClass="navbar navbar-expand-lg " class="fixed-top navbar-expand-md navbar-light white double-nav scrolling-navbar" [containerInside]="true" style="margin-top: 0px;">
    <mdb-navbar-brand>

    </mdb-navbar-brand>
    <links>

      <!-- Links -->
      <ul class="navbar-nav mr-auto">

      </ul>
      <!-- Links -->

      <!-- Search form -->
      <ul class="navbar-nav">
          <li class="nav-item active">
            <a class="nav-link waves-light" mdbWavesEffect><mdb-icon fas icon="phone" ></mdb-icon>  HOTLINE: (02) 5-318-8655(TOLL)<span class="sr-only">(current)</span></a>
          </li>
          <li class="nav-item">
              <a class="nav-link waves-light" mdbWavesEffect><mdb-icon fas icon="envelope" ></mdb-icon>  customercare@autosweeprfid.com<span class="sr-only">(current)</span></a>
          </li>

        </ul>
    </links>
</mdb-navbar>

这是第二次导航

<div class="container" style="margin-bottom: 1em; margin-top: 3em;">
    <mdb-navbar SideClass="navbar navbar-expand-lg scrolling-navbar intro-fixed-nav class z-depth-0" >

        <mdb-navbar-brand>
            <a class="navbar-brand" href="#">
                <img src="../../../assets/imgs/Autosweep-Logo-portrait-hi-res-1.jpg" height="100" class="d-inline-block align-top" alt="">
            </a>
        </mdb-navbar-brand>
        <links style="margin-left: 50px;">
            <ul class="navbar-nav" style="font-size: .8em;">
                <li class="nav-item active">
                    <a class="nav-link waves-light" mdbWavesEffect>Subscribe Now <span class="sr-only">(current)</span></a>
                </li>
                <li class="nav-item">
                    <a class="nav-link waves-light" mdbWavesEffect>Forms</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link waves-light" mdbWavesEffect>Balance Inquiry</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link waves-light" mdbWavesEffect>RFID Stations & Reloading Partners</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link waves-light" mdbWavesEffect>ADA Enrollment/Re-Activation</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link waves-light" mdbWavesEffect>Customer Care</a>
                </li>
            </ul>
        </links>
    </mdb-navbar>
</div>

它是这样的：

滚动第二个导航栏后消失：

我只是使用默认的引导程序。没有CSS修改。请帮忙。谢谢。