Input lag with other windows open

[SerynEngi]

Round ID: Various

Background: There seems to be escalating input lag upon moving around with other windows open, such as the portable crew monitor console or the stormdrive monitoring on the tablet.

Steps to reproduce:

1. Open up a console window (it appears as though any will do, but I am not sure)
2. Walk around for awhile, do standard things in round.
3. Note the input lag.
4. Close the connection to the server, and reopen it.
5. Note that the input lag has vanished and will not appear unless you repeat steps 1-3.

Byond client version is build 1542, in case that is relevant.