Input Transcript issue with gemini-live-2.5-flash-native-audio

[anupam-mishra]

I am using the gemini-live-2.5-flash-native-audio with my Google Agent development kit agent. Suddenly, it started generating input transcripts in Hindi, Chinese, and other random languages, even though I had explicitly instructed it in the prompt to use english. I tried disabling VAD and using ActivityStart and ActivityEnd instead, but the issue remains the same.

Environment details

• Programming language: Python
• OS: Any
• Language runtime version: 3.14.3
• Package version:
• google-genai==1.63.
• google-adk == "1.25.0"
• model= gemini-live-2.5-flash-native-audio

 run_config = RunConfig(
        streaming_mode=StreamingMode.BIDI,
        response_modalities=["AUDIO"], # Required for your PCM player
        input_audio_transcription=types.AudioTranscriptionConfig(),
        output_audio_transcription=types.AudioTranscriptionConfig(),
        session_resumption=types.SessionResumptionConfig(),
        context_window_compression=types.ContextWindowCompressionConfig(
            trigger_tokens=100000,  # Start compression at ~78% of 128k context
            sliding_window=types.SlidingWindow(
                target_tokens=80000  # Compress to ~62% of context, preserving recent turns
            )
        ),
        proactivity=types.ProactivityConfig(proactive_audio=True) if proactivity else None,
        enable_affective_dialog=affective_dialog,
        speech_config=types.SpeechConfig(
            voice_config=types.VoiceConfig(
                prebuilt_voice_config=types.PrebuiltVoiceConfig(
                    voice_name=os.getenv("AGENT_VOICE", "Puck")
                )
            ),
            language_code=os.getenv("AGENT_LANGUAGE", "en-US")
        )

Thanks!