We are invoking a BI Publisher report using PublicReportService.submitReport.
The report output is generated successfully.
The WCC/UCM delivery is also successful and a UCM Content ID is created.
However, the BI Publisher job status becomes Warning with:
Failed to call back ESS server [INSTANCE_ID=bip.bi_server1]
Manual execution/scheduling of the same report succeeds.
The issue occurs only when using submitReport.