first you should set the taxnomy in custom post type you have just set only for post title post content post comments you did not set for custom taxnomy
$post = array('tax_input' => [ array( <taxonomy> => <array | string> ) ] // For custom taxonomies. Default empty.
'page_template' => [ <string> ] // Requires name of template file, eg template.php. Default empty.
);
this query will set the custom taxnomy while creating custom post check this link