Yii2; code running in "else" block first, and then running code before "if" block?

I'm completely lost as to why this is happening, and it happens about 50% of the time.

I have a check to see if a user exists by email and last name, and if they do, run some code. If the user doesn't exist, then create the user, and then run some code.

I've done various testing with dummy data, and even if a user doesn't exist, it first creates them, but then runs the code in the "if" block.

Here's what I have.

if (User::existsByEmailAndLastName($params->email, $params->lastName)) {
    var_dump('user already exists');
} else {
    User::createNew($params);
    var_dump("Creating a new user...");
}

And here are the respective methods:

public static function existsByEmailAndLastName($email, $lastName) {
    return User::find()->where([
        'email' => $email,
    ])->andWhere([
        'last_name' => $lastName
    ])->one();
}


public static function createNew($params) {

    $user = new User;
    $user->first_name = $params->firstName;
    $user->last_name = $params->lastName;
    $user->email = $params->email;
    $user->address = $params->address;
    $user->address_2 = $params->address_2;
    $user->city = $params->city;
    $user->province = $params->province;
    $user->country = $params->country;
    $user->phone = $params->phone;
    $user->postal_code = $params->postal_code;

    return $user->insert();
}

I've tried flushing the cache. I've tried it with raw SQL queries using Yii::$app->db->createCommand(), but nothing seems to be working. I'm totally stumped.

Does anyone know why it would first create the user, and then do the check in the if statement?