Stable model complaining of policy violation but preview model is fine

I have developed an app which uses Vertex AI Gemini Live API and the models unpredictably start complaining of policy violation.

File “/code/.venv/lib/python3.11/site-packages/websockets/asyncio/connection.py”, line 322, in recv
raise self.protocol.close_exc from self.recv_exc
websockets.exceptions.ConnectionClosedError: received 1008 (policy violation) Publisher Model `projects/langtrak-adk-dev/locations/global/publishers/google/models/gemini-live-2.5-flash-native-audio` wa; then sent 1008 (policy violation) Publisher Model `projects/langtrak-adk-dev/locations/global/publishers/google/models/gemini-live-2.5-flash-native-audio` wa

In this case I switched to the preview model gemini-live-2.5-flash-native-audio → gemini-live-2.5-flash-preview-native-audio and the error is gone. Sometimes I have to do it vice versa.

My guess is that there are some infrastructure issues and its nothing do with my prompt or content.

Hopefully someone from Vertex AI can have a look.