<div class="container">
    <h1 class="my-4 text-white">This is a sticky menu</h1>
    <nav class="navbar navbar-expand-lg navbar-light bg-light" id="menu-demo">
  <a class="navbar-brand" href="#">Navbar</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item active">
        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Link</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Dropdown
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link disabled" href="#">Disabled</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>
  <h2 class="my-4">Check flicking when menu sticky actived</h2>
</div>

body {
  min-height: 1000px;
  background-color: #000;
}
.sticky {
  width: 100%;
  top: 0;
  left: 0;
  position: fixed;
  transition: all 1s;
}

function sticky_menu(menu, sticky) {
    if (typeof sticky === 'undefined' || !jQuery.isNumeric(sticky)) sticky = 0;
    if ($(window).scrollTop() >= sticky) {
        if ($('#just-for-height').length === 0) {
            menu.after('<div id="just-for-height" style="height:' + menu.height() + 'px"></div>')
        }
        menu.addClass("sticky");
    } else {
        menu.removeClass("sticky");
        $('#just-for-height').remove();
    }
}
$(document).ready(function () {
    var menu = $("#menu-demo");
    if (menu.length) {
        var sticky = menu.offset().top + 1;
        if ($(window).width() > 767) {
            sticky_menu(menu, sticky);
            $(window).on('scroll', function () {
                sticky_menu(menu, sticky);
            });
        }
    }
});