Live HLS playback never touched the viewer count: only the WebRTC path called IncrementViewerCount, so an HLS-only viewer showed as zero. Track sessions by the sid already threaded through every playlist/segment URL: the first request for a (streamer, sid) counts the viewer, and a session idle past 30s uncounts it via a janitor sweep. Media-playlist and segment requests are the heartbeat; master playlist fetches don't count, so one-shot fetchers (preview cards, health checks) aren't viewers. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>