WebRTC softphone initialization failing during Zendesk Talk migration for EU1 users

Could someone clarify why the Genesys WebRTC softphone fails to initialize for agents migrating from Zendesk Talk, specifically showing a ‘Media negotiation failed’ error in the browser console? We are using the Genesys Cloud Web Messaging SDK v1.2.4 and have configured the BYOC edge in Frankfurt for EU1 latency requirements. The Architect flow is correctly routing the call, but the client-side connection drops immediately upon answer. This mirrors a similar issue we faced with SAML assertions, where the mapping was technically correct but the handshake failed. Our Zendesk setup used a simple iframe embed, whereas Genesys requires a more complex WebSocket connection. The error log shows ‘RTCPeerConnection failed to create offer’ followed by a 403 Forbidden response from the media server. We have verified that the agents have the ‘Make and receive calls’ permission and are assigned to the correct skill group. The issue persists across Chrome and Firefox on Windows and Mac. Given our background in Zendesk, we expected a smoother transition to the WebRTC stack. Is there a specific configuration in the User Settings or the Architect flow that needs to be adjusted to allow the media stream to establish? We are concerned this might block our migration timeline for the next wave of agents.