I use standard demo example authentication, in basic version Yii2.
Server PHP :session.gc_maxlifetime = 1440
1. I open -
http://localhost/basic/web/index.php?r=site/login
Yii::$app->user->isGuest === 1
2. I write login and password: admin/admin
Yii::$app->user->login($this->getUser(), 60);
Yii::$app->user->isGuest === NULL
3. I close browser and web-server
4. I wait 3 day
5. I open browser, web-server and open site.
6. Yii::$app->user->isGuest === Null <------ Why?