Composer waterfall issues on US environment.

Update timeline

1. investigating Apr 27, 2026, 04:57 PM UTC

   We have found an issue with our priority rules for API interaction on server/edge in Composer. The dev team is currently investigating. Clients may find their list order being changed or unsorted without any user interaction. We will continue updating this incident once we identify the root cause.

2. investigating Apr 27, 2026, 06:37 PM UTC

   Our team has restored the priority rules to their pre-incident state while we continue to investigate the root cause. We advise customers to avoid making changes to priority rules until the investigation is complete. We will provide further updates as more information becomes available.

3. monitoring Apr 27, 2026, 10:01 PM UTC

   The issue has been identified and mitigated; we will continue monitoring the remediation.

4. resolved Apr 28, 2026, 09:20 AM UTC

   This incident has been resolved.

5. postmortem Apr 28, 2026, 02:04 PM UTC

   RCA report for the incident is available at [**this link**](https://docs.piano.io/wp-content/uploads/2026/04/2025-05-06-RCA-Experience-Priority-Data-Incident.pdf).