I edited the following core file because I was unable to make the change in my child theme. I need my CPT Template option to appear first in the Post Attributes — Template drop down list. I made it happen by editing: …/wp-admin/includes/meta-boxes.php, within the “default_page_template_title” filter.
I switched the order of two lines making my CPT Template appear on TOP.
<?php page_template_dropdown( $template, $post->post_type ); ?>
<option value=”default”><?php echo esc_html( $default_title ); ?></option>
How would I do this in the child theme?
Read more here:: CPT Template Option to Top