I am using Putty very often to SSH into Linux servers. In some cases, I won't leave the SSH session by typing exit, but by rebooting the remote machine.
Until one or two years ago, upon reboot, the OpenSSH server on the Linux machine obviously did notify Putty that the session has ended, which is what I want. Putty then used to close the session cleanly and immediately, and I could restart the session in no time (as soon as the rebooted server came back).
When I upgraded the Linux servers to Debian Wheezy or Jessie (I can't remember exactly), this useful behavior stopped. Now, when rebooting the remote servers, Putty doesn't get notified about the session end and tries to keep the session until it runs into timeout (after one minute or so).
Since I hadn't changed Putty's configuration for a long time, I suppose that the respective behavior of OpenSSH has changed. Although I have read the complete man page of OpenSSH, I could not find any option which (in my limited understanding) could be related to that problem, hence the question:
Is there a typical mistake in OpenSSH's configuration which could cause the "misbehavior"? Which option could be responsible?
EDIT:
This question might be a duplicate. But the solution / answer which is given in the duplicate does not work for me although I have the same setup as the OP. So something might be wrong with the solution given there, and I just thought it would be better to ask a new question instead of writing a comment to a question which has been asked over a year ago.