How to Fix a Unity Lobby Disappearing Because the Host Stopped Sending Heartbeats

A lobby that other players can see briefly and then can no longer find is almost always missing its heartbeat. Only the host needs to send it, and it must run on an interval shorter than the 30 second expiry. Here is how.

How to fix it

1. Heartbeat on a 15s interval

On the host, run a loop that calls await LobbyService.Instance.SendHeartbeatPingAsync(lobbyId) roughly every 15 seconds. Half the 30 second expiry gives margin for network jitter so the lobby never lapses.

2. Only the host should heartbeat

Clients must not send heartbeats; doing so wastes rate limit and can race the host. Guard the heartbeat loop behind a check that this player is the lobby host.

3. Stop and delete on shutdown

Cancel the heartbeat loop when the game starts or the host leaves, and call DeleteLobbyAsync so a stale lobby does not linger in matchmaking listings until it expires.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.