Stuck on Notification API WebSocket subscription handshake

NICE CXone API & Integrations
1

Stuck on establishing the Notification API WebSocket connection for real-time event ingestion. My gRPC service attempts to upgrade via the WebSocket endpoint but receives a 1006 abnormal closure immediately after the initial Sec-WebSocket-Accept response. I am passing a valid OAuth Bearer token in the Authorization header, yet the server drops the connection before I can send the subscription payload.

  1. Verified token validity via the OAuth provider.
  2. Confirmed endpoint matches the documentation for event streaming.

Any insights on why the handshake fails at this stage? Thanks.