First picture not appearing

Hello everyone,

I’m using the code below to show the pictures inside a project in a slider.
The very first image always appears as a thumbnail but once I start to slide pictures it doesn’t appear anymore. It only happens with the first one.

    <?php foreach ($album->images()->sortBy('sort') as $img): ?>
          <div class="swiper-slide"><img data-src="<?= $img->url() ?>" class="lazyload" alt=""></div>
    <?php endforeach ?>

Am I missing any part of the code?

Thanks in advance.

Seems there is no problem with the codes. Could it be due to the slider plugin? We can check if your site is live.