Why do invoices charge old payment method instead of default?

[hosthuski]

I continue to have this problem across multiple clients.

1. Client's credit card expires/doesn't work anymore so they add a new one as a payment method through the same gateway (Stripe) as the previous card. 
2. WHMCS attempts (and defaults on a per-invoice basis) to the old card and it fails payment despite the new card being added.
3. Client makes a ticket with support saying their invoices are failing even though their card is newly added.
4. I look and see the invoices failing to charge are trying to charge the old payment method and I then have to manually capture with the default payment method to get it to stop.

Is there a setting somewhere that I have to change to get this to work how it should be?

Expected behavior: when client adds new payment method and makes it DEFAULT, this payment method should be charged on any invoice including unpaid ones.

Actual behavior: when client adds new payment method and makes it DEFAULT, this payment method is ignored and NOT charged on any invoice, without manual intervention.

Edited April 18, 2022 by hosthuski