External webhook retries create duplicate tickets when the same event is replayed.

Context

• Region: North America
• Environment: web app
• Reporting team: Support
• Observed release: v1.12.0
• Impact level: critical

Reported Behavior

• External webhook retries create duplicate tickets when the same event is replayed.
• Scope: support workflows
• Root cause hint: workflow regression

Reproduction Steps

1. Send the same webhook payload twice.
2. Observe issue creation in the database.
3. Check whether an idempotency key is stored.

Expected Result

• The system should ignore duplicate webhook deliveries.

Investigation Notes

• Confirm the list and detail flows still support rapid triage.
• Requires deduplication logic.
• Often seen with unstable third-party retries.

Impact

• Agents have to merge or close duplicates manually.
• This issue affects North America customers and is prioritized as critical.