隐藏标题导航

Question

我需要查看标题，但固定顶部的导航栏隐藏标题。如果我删除了可以看到的固定最高成就，但是在滚动页面内部前进时，导航成就消失了。

<header>
  <div class="container">
      <div class="row">
        <div class="col">
          Acá debería ir la información de lo que deseo colocar. 
        </div>           
      </div>  
  </div>
</header>
<nav id="menu"class="navbar navbar-expand-lg navbar-light bg-light fixed-top">

    <a class="navbar-brand" href="#sec_inicio"><img img-responsive src="img/logo_farmacia2.png" alt="Farmacia" title="Imagen farmcia"></a>      
      <!--BOTON DE MENU EN TAMAÑO PEQUEÑO DE PANTALLA -->
      <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">

      <!-- ITEMS DE NAVEGACION -->
      <div class="navbar-nav ml-auto">
        <ul class="navbar-nav">

          <a class="nav-item nav-link active" href="#sec_inicio">INICIO<span class="sr-only">(current)</span></a>
          <li class="nav-item dropdown">
            <a class="nav-link" href="id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">INSTITUCIONAL</a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdown">
              <a class="dropdown-item" href="#sec_institucional">QUIENES SOMOS</a>
              <a class="dropdown-item" href="#sec_sucursales">SUCURSALES</a>
          </li>                 
          <li class="nav-item dropdown">
            <a class="nav-link" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">SERVICIOS</a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdown">
              <a class="dropdown-item" href="#sec_salud">SALUD</a>
              <a class="dropdown-item" href="#sec_consejos">CONSEJOS SALUDABLES</a>
              <div class="dropdown-divider"></div>                                       
              <a class="dropdown-item" href="#sec_far_turnos">FARMACIAS DE TURNO</a>
            </div>
          </li>         
            <a class="nav-item nav-link" href="#sec_ofertas">OFERTAS</a>
            <a class="nav-item nav-link" href="#sec_obras_sociales">OBRAS SOCIALES</a>         
            <a class="nav-item nav-link" href="#footer_main_contacto">CONTACTO</a> 
        </ul>
        </div>      
      </div>        
</nav>