Using transparent windows to show another game

Godot Version

4,3

Question

I have 3 monitors, placed vertically on top of each other. I have one game, which uses the bottom two monitors. I also have another game, which covers the top monitor, but also sometimes wants to cover the bottom monitor. I do this by setting the window to transparent and position two windows top and bottom. This should leave the middle monitor to always show the first game. Important: I want both games to always be on top.

Currently, I start the main game (bottom two screens) and then the second game (top + optional bottom). With my current settings, the main game always covers the second one. If I switch the load order, the first game is not even visible.

What is the best way to handle this situation? Should I just separate the second game in two?

why csharp ?