I have monitored the pid with strace, or think I did, as in the first post. It is a bash shell, but I it happens with : bash, ssh, zsh.

But essentialy is bash because the ssh connections are lunched using bash too.

If I comment the complete WINCH routine, like this

#$SIG{'WINCH'} = sub {
#    if (!$CONNECTED) {
#        return 1;
#    }
#    while (!$EXP->slave) {
#        #select(undef, undef, undef, 0.1);
#    };
#    $EXP->slave->clone_winsize_from(\*STDIN);
#    kill 'WINCH' => $EXP -> pid if $EXP -> pid;
#    return 1;
#};
[download]

It will not get disconnected, but the terminal will not be aware of the window size change

So, is in did something related to the propagation of the winch signal.