Piklist 0.9.9.8: Been tearing my hair out trying to figure out why I couldn’t change certain field values in meta-boxes; finally narrowed down the case. The problem occurs when the post-type supports ‘custom-fields’ and the meta-box has low or no priority set. I can set a value and save, but then cannot change the value.

See behavior here: http://recordit.co/VIS0mcZ7OS

Simpleton post type:

$post_types['simpleton'] = array(
	'labels' => piklist( 'post_type_labels', 'Simpleton' ),
	'public' => true,
	'rewrite' => false,
	'has_archive' => false,
	'menu_icon' => 'dashicons-smiley',
	'supports' => array(
		'title',
		'custom-fields',
	),
);

Meta boxes:

/*
Title: Test with priority: high
Post Type: post,simpleton
Priority: high
Order: 10
*/

piklist( 'field', array(
	'type' => 'text',
	'field' => 'test_high',
	'scope' => 'post_meta',
	'label' => 'Enter text',
));

/*
Title: Test with priority: low
Post Type: post,simpleton
Priority: low
Order: 10
*/

piklist( 'field', array(
	'type' => 'text',
	'field' => 'test_low',
	'scope' => 'post_meta',
	'label' => 'Enter text',
));

/*
Title: Test with no priority set
Post Type: post,simpleton
Order: 10
*/

piklist( 'field', array(
	'type' => 'text',
	'field' => 'test_nop',
	'scope' => 'post_meta',
	'label' => 'Enter text',
));

If I remove ‘custom-fields’ from the post_type supports clause, all three fields can be set and reset with no problem.

I have a testbed available; let me know if you want the keys.