Webhook delivery delayed

You consume webhooks from a payment provider to mark orders as paid. Around 13:00 merchants report orders stuck in 'pending payment' even though customers were charged. Dashboards: your webhook-receiver endpoint shows almost zero inbound webhook traffic for the last 30 minutes (a cliff, not a decline); your service health is green; the provider's status page notes 'delayed webhook delivery' on a degraded component. Charges themselves are succeeding via the synchronous API. How do you triage and mitigate?