I ended up figuring out the issue. I had to add new vars to the header
$archive_subheading = get_field( ‘archive_subheading’ );
Then I had to add the following conditional formatting to trigger the ACF code inside the loop.
<?php if( $archive_subheading ) : ?>
<h2 class=”customsub”><?php echo $archive_subheading ?></h2>
<?php endif; ?>
