Caused when the notification windows input region is set right after a
notification has been removed, before the AnimatedLists size-allocation
has been re-computed.

Can be reproduced by running this command in sway: `notify-send "test 1"
-u critical; notify-send "test 2" -t 2000; sleep 1; swaymsg "output *
power off"; notify-send "test 3" -t 500; sleep 3; swaymsg "output *
power on"`