diff --git a/docs/guides/remote-and-mobile.md b/docs/guides/remote-and-mobile.md
index aa914fb64bc..f7d93c680df 100644
--- a/docs/guides/remote-and-mobile.md
+++ b/docs/guides/remote-and-mobile.md
@@ -672,7 +672,18 @@ the browser holds, on the same clocks as [Session duration](#session-duration).
 ### Persistent SSH tunnel on macOS (LaunchAgent)
 
 A terminal-held tunnel dies with the terminal. A LaunchAgent survives reboots
-and reconnects after sleep. A ready-made plist is at
+and reconnects after sleep.
+
+If the desktop app should act only as a client for this remote gateway, turn off
+**Settings → Developer → Gateway → Run a local gateway**, then quit the app so
+its supervised gateway releases port 5476. Start the tunnel, verify the health
+probe below, and only then reopen the app. Turning the switch off does not create
+or supervise a tunnel; on the next launch the app expects a gateway to already
+answer on port 5476. A connected entry on the Instances page does not satisfy
+this requirement because those tunnels are supervised by the local gateway
+itself and use separate loopback ports.
+
+A ready-made plist is at
 [`assets/com.kirocrew.tunnel.plist`](assets/com.kirocrew.tunnel.plist):
 
 ```bash