Somehow I solved this. I read through the info on the repeater plugin page again and modified my code. Didn’t see any obvious changes, but this snippet is working now.
<?php if(get_field('summary_section')): ?>
<div class="section-head"><h2>Summary</h2></div>
<?php while(has_sub_field('summary_section')): ?>
<ul>
<li class="bulletin-data-item"><h3>Bulletin Summary</h3><?php the_sub_field('bulletin_summary'); ?></li>
<li class="bulletin-data-item"><h3>Location</h3><?php the_sub_field('location'); ?></li>
<li class="bulletin-data-item"><h3>Report Number</h3><?php the_sub_field('report_number'); ?></li>
<li class="bulletin-data-item"><h3>Incident Date</h3><?php the_sub_field('incident_date'); ?></li>
<li class="bulletin-data-item"><h3>Incident Time</h3><?php the_sub_field('incident_time'); ?></li>
</ul>
<?php endwhile; ?>
<?php endif; ?>
