Changing the taxonomy name fixes. I’ll wager the guess that having it called ‘type’ was conflicting with the Gutenberg js.
$args = array(
'labels' => $labels,
'hierarchical' => false,
'public' => true,
'show_ui' => true,
'show_admin_column' => true,
'show_in_nav_menus' => true,
'show_tagcloud' => false,
'show_in_rest' => true,
);
register_taxonomy( 'resource-type', array( 'resource' ), $args );