For some reason around 7 minutes, one of the instances lose all audio in it for the rest of the video. Mission 3 German Intermediate universalsplitscreen.github.io/
Universal split screen, it's a program that came before proto input, you have to use this one because it can block findwindow from stopping the second instance to run, unfortunately blocking the findwindow cause proto input to be unable to work on this so you have to use universal split screen to redirect keyboards and mouses