New custom fields not displaying

I am having a similar problem and unfortunately this solution did not work for me. I’m troubleshooting with my host (WP Engine) to see if I can find a workaround.

I believe the drop down menu that contains the custom field names has a default limit of 30. In order to see all unique custom field names you can increase the number of fields displayed to any custom number you would like.

Simply add this code to the functions.php file. The limit of 100 can be changed as needed. Hopefully that helps.

// Custom Field Limit for select / drop down menu
add_filter( ‘postmeta_form_limit’ , ‘customfield_limit_increase’ );
function customfield_limit_increase( $limit ) {
$limit = 100;
return $limit;
}