query on all archive pages only returning one post

I’m having a problem with the query on my date, categories and authors pages where they all only return one post. I’ve used identical code before, same plugins etc. and it’s worked. Are there any common reasons for a loop to only run once. The slug is fine and I’m arriving at the correct page, I’ve diasble headers and footers and other loops to check if there is another query interfering and nothing makes more than one post show up. I’m sure it’s something simple, but just not sure what.

Date is in a loop on date.php and authors similarly on authors.php, categories are a custom taxonomy so taxonomy-sections.php

My loop is:

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
content
<?php endwhile; ?>
<?php endif; ?>

The site is here: https://think-work-play.com/ check the catagories, authors, dates links at the bottom of the page. All the same result.