Error on laravel 5.6 Cashier

[lYesterdaYl]

https://laravel.com/docs/5.6/billing

Hi, my project uses laravel cashier to implement stripe API. It was working fine at the time I implemented Nov 2019. I am not sure what was changed. But the thing I see right now is the function "updateCard" did not properly update the stripe_id in the user table. Below is my code:

            $stripeToken = Token::create(array(
            "card" => array(
                    "number"    => $number,
                    "exp_month" => $exp_month,
                    "exp_year"  => $exp_year,
                    "cvc"       => $cvc,
                    "name"      => $name
                )
            ));

            $customer->updateCard($stripeToken->id);
            $response = $customer->charge($cart->base_grand_total * 100);

The error I got when the program is running updateCard function is

Could not determine which URL to request: Stripe\Customer instance has invalid ID:  {"exception":"[object] (Stripe\\Error\\InvalidRequest(code: 0): Could not determine which URL to request: Stripe\\Customer instance has invalid ID

Can anyone help on this? Thanks. Let me know if you need more information.