I've been trying out things with my game's splitscreen mode. I've added an option where instead of splitting the game's window in two to show both player's view, it instead opens a second window, and shows the second player's view on that. It lets player one and two have their own views without any split, and being in two windows, they can be positioned anywhere, and mainly, one can be put on the second screen.
This way works really nicely on it's own, and I've got remote play enabled on steam for the game.

You can play the normal single window, splitscreen mode just fine with Remote Play Together, it works perfectly.
The issue is it does not work when the game opens a second window for the two window multiplayer.

Once the second window opens, the person playing over Remote Play gets the "Live Broadcast, Please Stand By" image.
https://www.howtogeek.com/wp-content/uploads/2016/03/hts11-650x300.png.

Up until that point when the second window opens, the remote play session is working perfectly, it's just when the game opens the second window, steam tries to capture that one too or something, and just gets stuck not able to show it also.

Is this something I can fix? Or is it a bug with the Remote Play Together service itself?
Thanks for any help