Inbound Message flow: Participant attributes from Web Messaging missing in Architect Data Action

We are migrating our contact center logic from legacy scripts to Genesys Cloud Architect using Terraform for infrastructure management. The current challenge involves accessing participant attributes that were set via the Web Messaging channel before the interaction hits the Architect flow.

We have configured the Web Messaging channel to push custom attributes into the participant data. However, when the interaction routes to our Inbound Message flow, these attributes are not visible in the Data Action context. We attempted to retrieve them using a standard Get Participant Data action, but the JSON response only contains the core session identifiers and not our custom key-value pairs.

Here is the relevant snippet of the expected payload structure we are seeing in the browser console during the web widget session:

{
 "participant": {
 "id": "12345",
 "attributes": {
 "custom_ref": "ABC-123",
 "priority": "high"
 }
 }
}

The Data Action in Architect returns an empty object for attributes. Is there a specific API call required within the flow to hydrate this data, or does the Web Messaging channel require a different configuration to persist these attributes into the Architect context? We are using the latest provider version in our Terraform state. The flow ID is correct and the routing group is properly assigned.