It seems that there may be an issue with the integration of Bootstrap, JQuery, or Popper.js (or a combination of all three).
After inserting the following code:
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
into the <head>
, followed by:
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="56263926263324783c2516677867607866">[email protected]</a>/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
as the FINAL element before the </body>
tag, the functionality improved. Here is a CodePen demonstration I prepared:
https://codepen.io/jeffberlin/pen/ZEbPgvK
Regarding the hover effect, if you have specified a color for the element, you can modify it as follows:
.nav-link:hover {
color: red !important;
}