Thanks for reporting this @jgleeson, I did some log diving on this and it seems we are not cancelling trustly recurrings that fail due to the donor cancelling the subscription from their bank. Unfortunately this implies we have some more contributions in Civi from the recurring charge job that actually failed because of the Gravy - Trustly flow. @Cstone dropped an example here of such scenarios where a contribution is recorded on Civi because the initial status was capture_pending but eventually failed with cancelled_payment_method.

Gravy said they do not get a notification from the processor when the donor cancels their subscription, they only know the status after the payment method is charged.

Charging a payment method that has been cancelled would yield the error "splitToken is not valid" as you reported from Gravy.

Moving this ticket to done as the reason behind the error as being identified and the fix for that is covered in this phab ticket