No webhook received after prediction completes; prediction succeeds in dashboard but endpoint never called (or called but fails silently). Logs may show ConnectionRefusedError/MaxRetryError in Cog. Endpoint logs empty/missing requests. Possible duplicates if partial retries.[Replicate Docs](https://replicate.com/docs/topics/webhooks/receive-webhook) [Cog Issue](https://github.com/replicate/cog/issues/2229)

Webhook delivery fails if endpoint returns non-2xx (4xx/5xx), times out (>few seconds), or unreachable. Replicate retries terminal events ~1min max with exponential backoff but stops after. No retries for intermediate events. In self-hosted Cog, internal webhook sender blocks if service down.[Replicate Docs](https://replicate.com/docs/topics/webhooks/receive-webhook) [Cog Issue #2229](https://github.com/replicate/cog/issues/2229)