SQL returns null on left join?

Question

SQL

Hello! There are 2 tables users and invitations, the table of invitations stores who invited a certain user, if he came himself, then NULL. And I try to look for a certain period of time.
But the problem is with a certain period of time. always returns null when outputting data.
That is, I have displayed users for the entire period of time, I don’t know what to think of.

Structure:

--
-- Структура таблицы `inviteds`
--

CREATE TABLE `inviteds` (
  `id` int(10) UNSIGNED NOT NULL,
  `user_id` int(11) NOT NULL,
  `referer` int(11) DEFAULT NULL,
  `first` int(11) NOT NULL DEFAULT '0',
  `second` int(11) NOT NULL DEFAULT '0',
  `third` int(11) NOT NULL DEFAULT '0',
  `first_earn` double NOT NULL DEFAULT '0',
  `first_gth_earn` double NOT NULL DEFAULT '0',
  `second_earn` double NOT NULL DEFAULT '0',
  `second_gth_earn` double NOT NULL DEFAULT '0',
  `third_earn` double NOT NULL DEFAULT '0',
  `third_gth_earn` double NOT NULL DEFAULT '0',
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- --------------------------------------------------------

--
-- Структура таблицы `users`
--

CREATE TABLE `users` (
  `id` int(10) UNSIGNED NOT NULL,
  `name` varchar(190) COLLATE utf8mb4_unicode_ci NOT NULL,
  `email` varchar(190) COLLATE utf8mb4_unicode_ci NOT NULL,
  `token` varchar(190) COLLATE utf8mb4_unicode_ci NOT NULL,
  `balance` double NOT NULL DEFAULT '0',
  `tokens` decimal(8,2) NOT NULL DEFAULT '0.00',
  `role` int(11) NOT NULL DEFAULT '0',
  `password` varchar(190) COLLATE utf8mb4_unicode_ci NOT NULL,
  `cheater` int(11) NOT NULL DEFAULT '0',
  `banned` int(11) DEFAULT NULL,
  `active` int(11) NOT NULL DEFAULT '0',
  `ip` varchar(190) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `code` varchar(190) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `remember_token` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

The request itself:

SELECT * 
FROM   `inviteds` 
       LEFT JOIN `users` AS `refererJoin` 
              ON `referer` = `refererJoin`.`id` 
                 AND `refererJoin`.`active` = 1 
                 AND `refererJoin`.`banned` = 0 
       LEFT JOIN `users` AS `userJoin` 
              ON `user_id` = `userJoin`.`id` 
                 AND `userJoin`.`active` = 1 
                 AND `userJoin`.`banned` = 0 
                 AND `userJoin`.`created_at` > '2020-02-01 00:00:00' 
                 AND `userJoin`.`created_at` < '2020-03-01 00:00:00' 
WHERE  `referer` IS NOT NULL

Answer 1

WHERE `refererJoin`.`id` IS NOT NULL