WebSocket connection opens successfully but closes abruptly (often within ~10s) with close code 1011/NET-0001; logs show "Deepgram did not receive audio data or text message within timeout"; empty transcripts; no error event before close; occurs during silence, pauses, or initial no-data periods.

Deepgram enforces a 10-second timeout requiring at least one binary audio frame or text frame (e.g., KeepAlive) after connection open; failure due to no data sent (network blocks, empty packets, MediaRecorder resume issues without headers, or silence without keepalive+audio) triggers close code 1011 with NET-0001 payload.