Missing images - but only in some browsers!?

Hi, I wanted to make a page with pictures of people who work in our research group, so I hacked the “features” template of quark, replacing icons with images. So far so good, and when I was developing the page I mostly used safari. In safari, the page works fine all the time. The page is here:

https://anuquantumoptics.org/people-2

Then, I looked using chrome, and found that some fraction of the images were missing. When I reloaded, some of the missing images were loaded, while others disappeared. For sure, all of the images are available on the server, they load when I point the browser at them individually.

When I “inspect” a missing image chrome tells me:

Failed to load resource: the server responded with a status of 508 ()

So my question is, how can my simple page lead to an overload like this? I have 34 images, each about 40kB, so really not much.

The page is here if anyone wants to play and make suggestions!
https://anuquantumoptics.org/people

The hacked feature code, that builds the page, looks like this:

{% set grid_size = theme_var(‘grid-size’) %}
{% set columns = page.header.class == ‘small’ ? ‘col-3 col-md-4 col-sm-6’ : ‘col-4 col-md-6 col-sm-12’ %}

            {{ content|raw }}

            <div class="columns">
            {% for feature in page.header.features %}
               <div class="column {{ columns }}">
                  <div class="feature-image" style="font-weight: bold">
                     <img src="{{feature.image}}" width="100%" height="100%">
                     {% if feature.name %}
                      <br>  {{ feature.name }}
                     {% endif %}
                  </div>
                  <div class="feature-content">
                     {% if feature.text1 %}
                    {{ feature.text1 }} <br>
                     {% endif %}
                     {% if feature.text2 %}
                     {{ feature.text2 }} <br>
                     {% endif %}
                     {% if feature.url %}
                     <a href="{{feature.url}}">{{ feature.url_text }}</a>
                     {% endif %}
                  </div>
               </div>
            {% endfor %}
            </div>
        </div>
    </section>

Small update… I improved the situation a little by using lazyloading, as seen here:

https://anuquantumoptics.org/people

but if you scroll too fast, it gives the same error!