Requested device not found

Hi,

We're currently trying to migrate to LiveAvatar, and we're hitting an error when we start the session. We're getting this response from the start call:

{
"code": 1000,
"data": {
"session_id": "02d3a7dd-3120-4437-93d9-7ef14251c509",
"livekit_url": "wss://heygen-feapbkvq.livekit.cloud",
"livekit_client_token": "REDACTED",
"livekit_agent_token": null,
"max_session_duration": 60,
"ws_url": null
},
"message": "Session created successfully"
}

And then just after it reports the stream is ready, we get the following error out on the console:
Session start failed: NotFoundError: Requested device not found

We then get an event saying the stream quality is UNKNOWN and then we're disconnected from the room.

Does anyone know what's going on here?