Delivery retries can repeat an event when the receiver's acknowledgement is missing or unsuccessful. Your application needs to recognize the same event instead of repeating its customer-facing side effects. Two deliveries are not necessarily two distinct actions.
Compare event references and your receiver's response codes and times. Acknowledge only after handling the event according to your own durable processing design. If distinct events are being confused or retries continue after confirmed acknowledgements, share a small redacted sequence with support. Do not attach signing secrets or full customer payloads.