如何修复Bootstrap移动端下拉菜单展开时增大导航栏的问题

• 预期效果：
• 移动端实际显示效果：

下拉菜单在手机端展开时，会导致导航栏尺寸增大。

<div style=" background-image: url(https://i.imgur.com/408H5PI.jpg); background-size: cover; height: 100vh; background-attachment: fixed;">
<div class="sticky d-inline">
<!--导航栏开始-->
<nav class="navbar navbar-expand-lg navbar-light fixed-top" style="background: #285123; position: static;">
    <a class="navbar-brand" href="/"><img src="https://i.imgur.com/ui7PG0R.png" alt="text bajo" width="50px" height="50px"></img></a>
    
    </button>
    <div class="navbar-expand-lg" id="navbarNavDropdown">
      <ul class="navbar-nav navbar-expand-lg">
        <li class="nav-item dropdown float-right navbar-expand-lg">
          <a class="nav-link dropdown-toggle text-light" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
            分类
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
            {% for Category in category%}
            <a class="dropdown-item" href="{{url_for('get_category', id=Category.id)}}">{{Category.name}}</a>
            {% endfor %}
          </div>
        </li>
      </ul>
    </div>
  </nav>
</div>

内容的提问来源于stack exchange，提问作者Vracar