BYOC Edge v2.4.1 403 on Domain Registration

Issue Summary
POST request to /api/v2/boundary/domains throws a 403 Forbidden.

Environment & Configuration

• Edge Version: v2.4.1
• Current State: Stuck at REGISTERING_DOMAINS
• IAM Policies: Verified and correctly scoped
• Boundary Service: Will not accept the handshake despite valid policy configuration
• Licensing & Feature Toggles: Boundary domain capabilities are enabled per current roadmap specifications

Observations

• The boundary service consistently rejects the registration handshake at the API layer.
• Policy evaluation confirms appropriate permissions, yet the 403 response persists.

Reference Documentation

• Genesys Cloud Resource Center: Boundary Domain Configuration
• Genesys Cloud Resource Center: IAM Policy Requirements for Edge

Requesting technical guidance to resolve the handshake rejection.