can you try this so we can narrow things down.
while ($query->have_posts()): $query->the_post();
// because the image value is saved as attachment_id
$imgElement = get_field('character_image', get_the_ID());
$imgSrc = wp_get_attachment_image_src($imgElement, 'full');
echo "the image - ".$imgElement."<br>";
echo "the full size image src - ".$imgSrc;
endwhile;