<p dir="auto">I'm trying this demo:<br>
<a href="http://getbootstrap.com/javascript/#collapse" rel="nofollow">http://getbootstrap.com/javascript/#collapse</a><br>
If you open a tab then you click on a second one before the first is completely visible, than you get both panel opened.<br>
To try it I suggest to use keyboard to open the first panel then click in the second.</p>
<p dir="auto">Step 1. Navigate to this page: <a href="http://getbootstrap.com/javascript/#collapse" rel="nofollow">http://getbootstrap.com/javascript/#collapse</a><br>
Step 2. Click on one of the links that trigger opening of the accordion sections (ie. Collapsible Group Item <code class="notranslate">#1</code>)<br>
Step 3. Before the section's opening animation has a chance to complete (the one from 'Step 2' above) click on a different link to trigger opening a second panel (ie. Collapsible Group Item <code class="notranslate">#2</code>)</p>
<p dir="auto">At this point you should see that you have two accordion panels open at the same time.</p>