Node.js consumer dropping Analytics Notification WebSocket frames

Getting dropped connections when trying to pipe Analytics Notification events to Kafka. Using the JS SDK to subscribe to the stream. The client connects, pushes a few spans, then the socket hangs. Here’s the setup:

const client = new PlatformClient.PlatformClient();
client.login(...);
const ws = client.getWebSocketClient();
ws.subscribe('/v2/analytics/conversations/summary', ...);

The on('data') handler stops firing after ~60 seconds. No error callback, just silence. Is there a keep-alive I’m missing or a rate limit on the notification stream?