Why would this nav not show on iPhone 13 Safari? - html

Question

I have a website that has a <nav> element at the top where it shows main menu links and a number of other things.
For years it worked just fine across all devices ever tested against (even Microsoft) just not on iPhone 13.
<header class="wrapper header">
<nav class="navbar top navbar-top navbar-expand-lg d-print-none navbar-primary bg-primary text-white fixed-top ">
<a class="navbar-brand" href="/?ref=top_brand_logo">MyWebsite</a>
<div class="mobile-navbar-items d-sm-inline-block d-xs-inline-block d-md-none d-lg-none d-xl-none">
<div class="navbar-text">Hello User!</div>
</div>
<button id="menuButton" class="navbar-toggler" type="button" data-toggle="collapse" data-target="#top-navbar" aria-controls="top-navbar" aria-expanded="false" aria-label="Toggle navigation">X</button>
<div class="collapse navbar-collapse" id="top-navbar">
<ul class="navbar-nav mr-auto mt-2 mt-lg-0">
<li class="nav-item">
<a class="nav-link" href="link1">Link1</a>
</li>
<li class="nav-item">
<a class="nav-link" href="link2">Link2</a>
</li>
<li class="nav-item">
<a class="nav-link" href="link3">Link3</a>
</li>
</ul>
<div class="navbar-text d-sm-none d-xs-none d-md-inline-block d-lg-inline-block d-xl-inline-block">
Hello Mr Lebowski!
</div>
<ul class="navbar-nav right">
<li class="nav-item">
Log out
</li>
</ul>
</div>
</nav>
</header>
I just don't get it. Have they removed support for <header> or <nav> in the latest iOs Safari? Am I doing something wrong?