the daemon never sent a client its own Moved or Resized, and the events carry no order, so with two editors changing one terminal at once, the one the daemon applied last got the other's older event afterwards and ended up disagreeing with the daemon.
the daemon now sends these events to every client, the mover included, so each client sees the daemon's final state last. a client skips its own echo unless it matches the last position or grid it sent, so the echoes of a drag do not pull the window back.