Bootstrap tabs not working the first time

Question

I am trying to implement two basic tabs and panels. The panel does not show the content(Page 1) on page load. However, clicking on the other tab works fine with the right content(Page 2) and then going back to the first tab works fine(Page 1).

<ul class="nav nav-tabs">
    <li class="active"><a href="#panel1" data-toggle="tab">Page 1</a></li>
    <li><a href="#panel2" data-toggle="tab">Page 2</a></li>
</ul>

<div class="tab-content">
    <div id="panel1" class="tab-pane">
        Page 1
    </div>
    <div id="panel2" class="tab-pane">
        Page 2
    </div>
</div>

Is there something I am missing?

Answer 1

You don't have the active class for the content panel. You need the following to show the panel1 content by default:

<div id="panel1" class="tab-pane show active">...

Answer 2

I think we need more details because your code is working fine

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>

<ul class="nav nav-tabs">
    <li class="active"><a href="#panel1" data-toggle="tab">Page 1</a></li>
    <li><a href="#panel2" data-toggle="tab">Page 2</a></li>
</ul>

<div class="tab-content">
    <div id="panel1" class="tab-pane show active">
       This is the content of page1............................
    </div>
    <div id="panel2" class="tab-pane">
       This is the content of page2............................
    </div>
</div>