I have been integrating with the Uber Delivery API for a while now and things have been going well. However, a week ago, a delivery was posted to the API and the status of the delivery remained as "processing" for at least 20 minutes. Because the delivery was time sensitive for our company, we needed to cancel this delivery and schedule a new one. Is this supposed to happen? I would think that the "processing" status would eventually time out and then display a failure status.
Processing does time out if Uber deliveries cannot find a driver (no_couriers_available). This is where deliveries spend 30 minutes in a state looking for a courier.
There is a DELETE method on /v1/deliveries/:id for cancelling in progress ones (as you used).