I have just uploaded a quick Client patch that should fix several issues:
-Fixed game being still inactive after alt+tab sometimes.
-Fixed mouse and keyboard being laggy when Keyboard layout is set to Korean.
-Fixed Shift key not working for movement holding when chat bar is opened.
-Fixed X button not closing game but prompting to log out instead.
-Fixed Enter on logout dialog not pressing Ok.
-Fixed several text issues.
-Fixed various minor bugs.
You can get it through updater.