Why doesn't Yii::$app->set set parameters?

Question

Yii

I work with several e-mail addresses with the yii2-imap
extension. I create a new config for imap connection in the constructor method:

public function __Construct($username, $password) {
        
        $this->address = $username;

        Yii::$app->set('mailer', [
            'class' => 'yii\swiftmailer\Mailer',
            'transport' => [
                'class' => 'Swift_SmtpTransport',
                // Values from db
                'class' => 'Swift_SmtpTransport',
                'host' => 'smtp.gmail.com',
                'username' => $username,
                'password' => $password,
                'port' => '587',
                'encryption' => 'tls',
            ],
        ]);

        Yii::$app->set('imap', [
            'class' => 'roopz\imap\Imap',
            'connection' => [
                  'imapPath' => '{imap.gmail.com:993/imap/ssl}INBOX',
                  'imapLogin' => $username,
                  'imapPassword' => $password,
                  'serverEncoding'=>'utf-8', 
                  'attachmentsDir'=>'/'
            ]
        ]);


       ;
   }

The code worked, but fell off and it is not clear why.
The new object for the new mail still has the old connection.
Those. or Yii::$app->set doesn't start (for new config parameters), why?
Either you need to restart the yii application (how?)
Or interrupt the previous connection (there is no method in this extension, but I don’t think it will help, because the object is created new, but the problem is in the config).
What will be the advice?