AppFoundry Cognigy WebSocket drops after 30s despite keep-alive

The WebSocket to our Cognigy bot keeps timing out after exactly 30 seconds. The container logs show a clean close, but the audio stream cuts out instantly. We’re using the standard wss://api-gw.usw2.pure.cloud/ endpoint. Here’s the config:

{"keepAliveInterval": 25000, "reconnect": true}

Nothing in the logs indicates an error code. It just dies. We’ve tried increasing the timeout in the Architect flow but it makes no difference. Is there a specific header or payload we’re missing to keep the connection alive?