Hyperlink doesn't redirect while others do

Question

I'm having a free template from Creative Tim. It's called Paper Kit 2 and you can find it here:

The problem I have is, when I create a hyperlink from the <h1> tag that read Paper Kit 2 and the <h2> tag that read Make your mark with a free bootstrap 4 UI Kit! they aren't working. They don't redirect me to href="https://www.creative-tim.com" But the buttons and icons in the top bar do bring me to the corresponding pages. The HTML code is:

<div class="page-header section-dark" style="background-image: url('./assets/img/antoine-barres.jpg')">
    <div class="filter"></div>
    <div class="content-center">
      <div class="container">
        <div class="title-brand">
          <a href="https://www.creative-tim.com">
            <h1 class="presentation-title">Paper Kit 2</h1>
          </a>

          <div class="fog-low">
            <img src="./assets/img/fog-low.png" alt="">
          </div>
          <div class="fog-low right">
            <img src="./assets/img/fog-low.png" alt="">
          </div>
        </div>
        <a href="https://www.creative-tim.com">
          <h2 class="presentation-subtitle text-center">Make your mark with a Free Bootstrap 4 UI Kit! </h2>
        </a>

      </div>
    </div>
    <div class="moving-clouds" style="background-image: url('./assets/img/clouds.png'); "></div>
    <h6 class="category category-absolute">Designed and coded by
      <a href="https://www.creative-tim.com" target="_blank">
        <img src="./assets/img/creative-tim-white-slim2.png" class="creative-tim-logo">
      </a>
    </h6>
  </div>

I looked it up on the stackoverflow forum and I read something about javascript interfering. That post refers to an issue on a GitHub page but I don't understand what they explain there.

Can someone shed a light on this issue and why some hyperlinks work correct and others not (redirecting).