Just noticed that the messaging API returns a 422 Unprocessable Entity error when attempting to attach custom metadata to sessions initiated via our SG1 BYOC trunks.
The standard PSTN channels accept the same payload structure without issue, but the SIP trunked digital sessions fail at the /api/v2/conversations/messaging/attachments endpoint. The error response indicates a validation failure on the ‘channelType’ field, specifically rejecting ‘sip’ as an invalid value for metadata attachment, despite the session being active and visible in the admin console. We are using the Genesys Cloud Messaging SDK v2.1.4 for our integration layer. The issue persists across all 15 BYOC trunks managed in the APAC region, suggesting a platform-side validation quirk rather than a configuration error on our end. The SIP registration status is healthy, and failover logic has not triggered, so connectivity is not the root cause. Has anyone encountered similar restrictions on metadata tagging for SIP-based digital channels? We need this data for our analytics reporting pipeline, and the current workaround involves manual tagging which is not scalable. Any insights into whether this is a known limitation or a bug in the current API version would be appreciated.