Hi! Great video and great project. Congrats! I just wanted to say that the black background problem appears for me even though I have the latest Nvidia driver with a 3070. I'm not sure what could cause that problem. I have the new Nvidia app if that helps.
Edit: I've found a post. Maybe it can help you if you want to fix it? https://forum.godotengine.org/t/transparent-background-show-black/52877/6