Membership + donation fails
Create a Contribution Page for Membership with 'Contribution Amounts section enabled' ticked, and on the Membership tab 'Separate Membership Payment' ticked.
If the user purchases membership only, payment works. If they add a donation it fails with: "This PaymentIntent's amount could not be updated because it has a status of requires_capture. You may only update the amount of a PaymentIntent with one of the following statuses: requires_payment_method, requires_confirmation.",
Tested with 6.3.alpha1 & mjwshared 0.6.beta1