I've been trying to figure this out for a while now. I'm a bit of a noob when it comes to Bootstrap, so please allow me the probably simple question. I'm trying to create a navbar with bootstrap 4, with the majority of menu items on the left, but with the login button on the right. I've figured some roundabout way of doing it (which could be wrong) but whenever I view the page in phone or tablet view, the 'login' item of the menu doesn't appear when one clicks the burger menu icon. It appears up to a point (think it's about 760px) and then just disappears from view. Here's the markup to this point, any help at all would be appreciated.
<a class="navbar-brand" href="#"><img src="imgs/branding/nerve logo_small.png" width="50" height="50" alt=""></a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="index.php">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Features</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Placeholder 1</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Placeholder 2</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Placeholder 3</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Placeholder 4</a>
</li>
</ul>
</div>
<ul class="navbar-nav flex-row ml-md-auto d-none d-md-flex">
<li class="nav-item text-right">
<a class="nav-link " href="#">Login</a>
</li>
</ul>
</nav>