PC → Mac: pointer can't cross to the Mac after a few idle minutes; connection is only declared dead ~2 min later

[Not-Nailec]

Setup: Beamer 1.4.2 on a MacBook Air (Apple silicon, macOS 27) and a Windows 11 PC on the same LAN. Windows on the left, Mac on the right.

What happened
After a few minutes (3–4 at most) without using the other machine, I pushed the pointer off the PC's edge to go to the Mac. Nothing happened. The Beamer window on the PC still showed the connection as active. Moving the Mac's trackpad and pushing the pointer through the Mac's edge back to the PC did work, so the link was not really usable from the PC side.

Mac log around the incident (IP redacted)

23:16:55 INFO  Beamer-session Pointer pushed through the right edge; returning input to the PC
23:19:07 ERROR Beamer-ack-watchdog Windows stopped responding; connection dropped and input forced local
23:19:07 ERROR Beamer-ack-receiver ACK receive failed: [Errno 9] Bad file descriptor; connection dropped and input forced local
23:19:07 WARNING Beamer-session <pc-ip> went quiet; treating the connection as dead
23:19:09 WARNING Beamer-connection connection to Windows failed: timed out
23:19:12 WARNING Beamer-connection connection to Windows failed: timed out
23:19:14 INFO  Beamer-connection connected to Windows at <pc-ip>:24820
23:19:16 INFO  Beamer-session Authenticated <pc-ip> (protocol v5)

So the Mac only noticed the dead connection about 2 minutes after the last activity, then reconnected by itself in ~7 s.

Guess
The connection went silently stale while idle (PC or Wi-Fi power saving?), and neither side noticed until the watchdog fired. During that window the PC still showed 'connected' and the switch did nothing.

Suggestions

• Shorter keepalive/heartbeat so a stale link is detected in a few seconds.
• Show the real link state in the PC UI (not 'connected' when the Mac stopped answering).
• If the switch is attempted while the link is stale, trigger an immediate reconnect instead of doing nothing.

[TK9443]

Thanks for the log, it helps a lot. Both apps already ping each other every second and drop the link after two seconds without a reply, so a shorter heartbeat isn't the fix. In your Mac log, three separate timers all fired at 23:19:07, over two minutes late, which looks like the Mac was asleep until you touched the trackpad, then took a few seconds to get back on Wi-Fi.

Two things would pin it down, and you can add both here in a comment like you did the Mac log:

1. The PC's log from the same minutes. Right-click Beamer in the tray, choose Open log folder, and drag Beamer.log into a comment, or paste the lines from around that time.
2. On the Mac, run pmset -g log | grep -E 'Sleep|Wake' in Terminal and paste what it prints for 23:16 to 23:19.

You're right that pushing into the edge should say something when the Mac can't be reached. Today only the switch shortcut tells you.