Updaded Windows 10 to 11 yesterday and today I wanted to play against 2 extreme AI’s and the game slows down at regular intervals. In the video, see the timer near the end. That cycle repeats in what it seems to be regular intervals.
UPDATE: I got more information. With Task Manager open and Always on Top, I see the nVidia card droping from 70% usage to 16% usage when the game slows down (for whatever reason). So the culprit is video rendering. Why it does this? I don’t know.
@SavageEmpire566 could you point me in the right direction to obtain speedy support? Because this might be happening to me only. What would be the speediest way to get a dev or technician to look at my setup and maybe collect logs or similar?
@webJose @anon63664082 also, if you’d be so kind to share the results of your support request, it may be helpful for others later on 
@SavageEmpire566 Hi. I have just concluded my conversations with the standard support personnel and they have exhausted all troubleshooting steps and have forwarded this issue to the Development team (so I guess you and your buddies).
If you need anything from me let me know. This is happening only with an external monitor plugged in, laptop closed.
I have no idea what support had you try, but as always make sure your drivers are updated/correct. Might also want to include SSD firmware in this check. You might also try reducing the quality settings just to see if you can get it to run smoothly at all, even if it ran smoothly at higher settings previously on Win 10.
If you have a fancy gaming mouse, try lowering the response rate. Anecdotally had a friend switch to Win 11 early on and I believe he went from a wired to a wireless mouse and it fixed his performance issue oddly (could have been the other way around, I don’t quite remember).
You can also try disabling the Gamebar/GameDVR that ships with Win11 and see if that helps anything.
Thanks. Yes, all seems to be up to date. Literally the problem appears by just plugging in the external monitor and closing the laptop. Disconnect the monitor and play in the monitor’s laptop and the problem doesn’t present itself.
Ok, 2 weeks have passed since I raised this problem with game support, it was allegedly escalated and NOBODY followed up.
I have more information: The GPU works OK if the game window loses focus. For example: My current setup is like this: Closed laptop connected to an LG UltraFine monitor through HDMI running 4K @60 Hz. I open the game and I open Task Manager (Windows 11 Home) in Always On Top mode.
I start a game. 3D rendering is at a very low percentage, and the game progresses at a super, super low pace. If I click on Task Manager using the mouse, making the game screen lose focus, 3D rendering picks up and the game can be seen running normally, but since the window doesn’t have the keyboard focus, I cannot really play. If I click on the game window again, 3D rendering goes to hell one more time.
NOTE: Whenever I say “game window”, note that the window is in fullscreen mode.
Found this post:
Particularly, there’s an answer that people seem to like: Unplug the monitor and plug it back in. They say the problem goes away. It did not in my case. Just by Alt-Tab’ing 3D rendering comes back up. This is incredibly annoying and did not use to happen. What goes on???
@SavageEmpire566 your mates at support are a no-show. Any help you can provide??
UPDATE: In the thread I showed above from nVidia, I found this:
It states that nVidia hid an option for multi-monitor support. I used the thrid party tool there to enable multi monitor support and the original problem went away. While I was able to play, the game lagged for the most part. Dunno if it was due to population count from my civ plus the 2 extreme AI civs or if it showed a different performance issue.
So thanks for nothing, Microsoft support.
It sounds like the entirety of the game didn’t lag, just in late-game?
Have you played more than one game? Is this lag always present?