Second custom post type breaking the first

I’ve added custom posts for years and never had problems, but today is a first.

I’ve added my first CPT and it works fine, I then wanted to add a second CPT and now the first doesn’t appear and ‘Page not found’

This is my code;

add_action("init", "custom_post_types");
function custom_post_types()
{

    register_post_type('products', 
        array('label' => __('Products','templatic'),
            'labels' => array(  'name' => __('Products','templatic'),
            'singular_name' => __('Product','templatic'),
            'add_new' => __('Add Product','templatic'),
            'add_new_item'=> __('Add New Products','templatic'),
            'edit' => __('Edit','templatic'),
            'edit_item'=> __('Edit Product','templatic'),
            'new_item' => __('New Product','templatic'),
            'view_item' => __('View Products','templatic'),
            'search_items' => __('Search Products','templatic'),
            'not_found' => __('No Products found','templatic'),
            'not_found_in_trash'=> __('No Products found in trash','templatic')   
           ),
            'public'            => true,
            'can_export'        => true,
            'show_ui'           => true, // UI in admin panel
            '_builtin'          => false, // It's a custom post type, not built in
            '_edit_link'        => 'post.php?post=%d',
            'capability_type'   => 'post',
            'menu_icon'         => 'dashicons-cart',
            'hierarchical'      => false,
            'rewrite'           => array("slug" => "products"), // Permalinks
            'query_var'         => "true", // This goes to the WP_Query schema
            'supports'          => array(   'title',
                                            'thumbnail',
                                            'editor', 
                                            'revisions') ,
            'show_in_nav_menus' => true ,
        )
    ); 

    register_post_type('accessories', 
        array('label' => __('Accessories','templatic'),
            'labels' => array(  'name' => __('Accessories','templatic'),
            'singular_name' => __('Accessory','templatic'),
            'add_new' => __('Add Accessory','templatic'),
            'add_new_item'=> __('Add New Accessories','templatic'),
            'edit' => __('Edit','templatic'),
            'edit_item'=> __('Edit Accessory','templatic'),
            'new_item' => __('New Accessory','templatic'),
            'view_item' => __('View Accessories','templatic'),
            'search_items' => __('Search Accessories','templatic'),
            'not_found' => __('No Accessories found','templatic'),
            'not_found_in_trash'=> __('No Accessories found in trash','templatic')   
           ),
            'public'            => true,
            'can_export'        => true,
            'show_ui'           => true, // UI in admin panel
            '_builtin'          => false, // It's a custom post type, not built in
            '_edit_link'        => 'post.php?post=%d',
            'capability_type'   => 'post',
            'menu_icon'         => 'dashicons-screenoptions',
            'hierarchical'      => false,
            'rewrite'           => array("slug" => "accessory"), // Permalinks
            'query_var'         => "true", // This goes to the WP_Query schema
            'supports'          => array(   'title',
                                            'thumbnail',
                                            'editor', 
                                            'revisions') ,
            'show_in_nav_menus' => true ,
        )
    );   

}

I’ve got two single files;
single-products.php
single-accessories.php

When I delete the accessories CPT, products re-appears. I wonder if I’ve made a mistake somewhere but can’t see it….