A closed tab no longer keeps the server busy for it

When you closed a tab, the server did clean up your session — but the parts of the system that had been sending you live updates were told only that your session "could not be reached right now", the same message they get while the platform is being updated. They treated it as temporary, as they should during an update, and kept trying: hundreds of refused deliveries a minute, for as long as three quarters of an hour, for a single closed tab. Users saw the platform slow down and, for the person whose tab it was, sessions that kept dropping.

Now a closed session is remembered as closed for a short while, so the first attempt to reach it is answered with "this session is gone" rather than "not right now". The sender stops at once. Sessions that are genuinely just moving during an update still get the "not right now" answer and still wait for it, exactly as before.