Up until a few days ago, I was able to run Starcraft 2 in Borderless Windowed mode with no issues. After having a friend’s discord stream up, Starcraft is no longer using any cpu in borderless windowed mode and goes to a very low framerate unless I have a stream open.
If I have a stream up (Tried in Discord and with Twitch) either on the same monitor behind Starcraft, or on my other monitor, it runs completely fine. If I change tabs from the stream, not even needing to close it, the issue comes up again.
The game runs completely fine in full screen and usually hits ~10-14% CPU usage. I disabled the Discord overlay to see if that would help, it did not. I have also tried unplugging my other monitor and still have the same issue.
No other games running in Borderless Windowed mode are having this issue either.
Another thing, when the game is not the focus, it uses the CPU and goes to a more normal looking framerate.