When a machine is turned off, or there is some network issue, the client will currently state "Connection to server tl.example.com timed out. Check your settings.", which isn't completely correct. Although such an issue can in some cases result in a timeout, it is very surprising when the network knows the machine is unreachable and you get that error message immediately after you've pressed connect. This is fallout from bug 4171 where we changed this error message from something more general that we had from bug 3296.
We saw this with our internal system as a result of fail2ban and too many incorrect login attempts: > 2022-01-05T14:10:44: ssh[E]: CONNECT ERROR: 65 > 2022-01-05T14:10:57: Process 83970 exited with code 255