It’s not a bug, it is intended behavior by CCP. Open your FPS monitor and it will show you a status for “FPS Throttling”. Not something a Windows option or driver update is going to fix. What you need is a program that can force specific unfocused windows to remain active without taking input events from other windows. Unfortunately, ISBoxer is the only program able to do this.
If you end up getting it or have it already, the setting for this can be found under the General tab in your character set.
