comment.delivery_unconfirmed
An outgoing comment failed in a way that could mean it was posted. It is not sent again - Postproxy checks the platform for it instead. Not terminal.
postWebhookcomment.delivery_unconfirmed
Payload
Response
Acknowledged
Changes
Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.