It is not recommended to include Bootstrap links in your project and remove any inline styles from your files. I have successfully resolved the error and everything is functioning perfectly. You can test this HTML file in your project directory and execute it.
<html>
<head>
<link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
<link rel="stylesheet" type="text/css" href="custom-styles/style.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
</head>
<body>
<div class="grid-wrap">
<div class="col-lg-12 offset-top-40">
<div data-grid-layout="fitRows" data-grid-group="gallery" class="grid grid--loaded" style="position: relative; height: 2300px;">
<div class="row">
<div data-filter="All" class="col-xs-12 col-sm-6 col-lg-4 grid-item">
<div class="inset-xl-left-30 inset-xl-right-30">
<a class="grid-classic" href="index.html" target="_blank">
<figure>
<img class="img-responsive" src="img/image1.jpg" alt="">
<figcaption class="grid-classic-caption text-center">
<h4 class="grid-classic-title text-dark" style="font-family: 'Roboto', sans-serif; color: #333;text-transform: uppercase; text-align: center; font-weight: 400">Image 1</h4>
<p class="grid-classic-desc text-regular veil reveal-xs-block" style="font-family: 'Roboto', sans-serif;text-transform: uppercase;font-weight: 400;text-align: center;">Description 1</p>
</figcaption>
</figure>
</a>
</div>
</div>
<div data-filter="All" class="col-xs-12 col-sm-6 col-lg-4 grid-item" >
<div class="inset-xl-left-30 inset-xl-right-30">
<a class="grid-classic" href="index.html" target="_blank">
<figure>
<img class="img-responsive" src="img/image2.jpg" alt="">
<figcaption class="grid-classic-caption text-center">
<h4 class="grid-classic-title text-dark" style="font-family: 'Roboto', sans-serif; color: #333;text-transform: uppercase; text-align: center; font-weight: 400">Image 2</h4>
<p class="grid-classic-desc text-regular veil reveal-xs-block" style="font-family: 'Roboto', sans-serif;text-transform: uppercase;font-weight: 400;text-align: center;">Description 2</p>
</figcaption>
</figure>
</a>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>