Hi @tylerkd
That’s weird. Could you please check if there are any differences between the values posted from AJAX and backend in the wp_postmeta
table? Also, could you please try to update the field by using the field key like this:
update_field('field_1234567890abc', $volunteers, $cleanup_id);
Where “field_1234567890abc” is the field key.
Thanks 🙂