Hiii!

I'm trying to set up a way I can play multiplayer game as coop with my friends. I plan on using 2 steam account at the same time. All of this works as planed. The problem I have is I can't have 2 games focused at the same time. So if I play with asdw and my friend a controller or arrow keys, the input will only go to one of the two games (the one in focus).
The only way to move the other character in game 2 is to alt tab or move my mouse and click on game 2 window, and then the same if I want to be able to move character 1 in game 1 window.

I saw a youtube video how they was able to run both games at the same time and have both games in focus, with funtion "Prevent Windows Deactivation (Keeps game windows focused)"
I have tried to do the same but no success. In my testing I have been useing both steam games and non steam games. The funtion do something, I hear it activating and it dosn't minimising when I tab down if I using fullscreen as it would do without it. I also use windows 11.
I have tried using it as in the video, hotkey it and using it as a trigger. Run it with adminis... (both displayfusion and the game) and of course restarted my pc.

Here is the video I was watching: https://www.youtube.com/watch?v=VfNVOAmB6m8&t=81s

Anyone who can help who have more knowless then me ;-;

Thx for ur answer <3