Yes, I only installed the Toolset Access plugin because we only need access to those features. If you believe I should have installed extra plugins please let me know which ones and why.
Yes, the post type and taxonomy are different (event and events), but the events taxonomy has the 'event' slug so that we don' end out with the URL "/event/events/name-of-event/", instead we use "/event/name-of-event/". It has worked fine for us so far and it would take a lot of work to change it now. Do you believe this is why Toolset is not recognising the "event" post type?
Here's the code used to create this specific post type and taxonomy.
register_post_type('event', [
'description' => 'Retreats, Novenas and other specific events.',
'public' => true,
'hierarchical' => false,
'has_archive' => true,
'public' => true,
'publicly_queryable' => true,
'query_var' => true,
'show_ui' => true,
'show_in_rest' => true,
'show_in_menu' => true,
'show_in_nav_menus' => true,
'exclude_from_search' => false,
'can_export' => true,
'menu_position' => 5,
'menu_icon' => 'dashicons-megaphone',
'supports' => ['title', 'editor', 'thumbnail', 'author', 'revisions', 'comments'],
'rewrite' => ['slug' => 'event', 'with_front' => true],
'labels' => [
'name' => __('Events', 'sacred-space-plugin'),
'singular_name' => __('Events', 'sacred-space-plugin'),
'add_new_item' => __('Add new Event', 'sacred-space-plugin'),
'new_item' => __('New Event', 'sacred-space-plugin'),
'view_item' => __('View Event', 'sacred-space-plugin'),
'not_found' => __('No Events found', 'sacred-space-plugin'),
'not_found_in_trash' => __('No Events found in trash', 'sacred-space-plugin'),
'all_items' => __('All Events', 'sacred-space-plugin'),
'insert_into_item' => __('Insert into Events', 'sacred-space-plugin')
],
]);
register_taxonomy('events', ['event'], [
'label' => __('Event Series', 'txtdomain'),
'hierarchical' => true,
'show_admin_column' => true,
'show_in_rest' => true,
'labels' => [
'singular_name' => __('Event Series', 'txtdomain'),
'all_items' => __('All Event Series', 'txtdomain'),
'edit_item' => __('Edit Event Series', 'txtdomain'),
'view_item' => __('View Event Series', 'txtdomain'),
'update_item' => __('Update Event Series', 'txtdomain'),
'add_new_item' => __('Add New Event Series', 'txtdomain'),
'new_item_name' => __('New Event Series', 'txtdomain'),
'search_items' => __('Search Event Series', 'txtdomain'),
'popular_items' => __('Popular Event Series', 'txtdomain'),
'parent_item' => __('Parent Event Series', 'txtdomain'),
'separate_items_with_commas' => __('Separate Event Series with comma', 'txtdomain'),
'choose_from_most_used' => __('Choose from most used Event Series', 'txtdomain'),
'not_found' => __('No Event Series found', 'txtdomain'),
]
]);
register_taxonomy_for_object_type('series', 'events');