What is your Windows version, and do you use multiple monitors ?
I'm on windows 11 on a laptop, so just one screen. The first time I ran it, it only covered the screen from the bottom right corner but was still solid black in the corner. Then restarting the game made the entire screen black with the UI. The game has started correctly and I am able to interact with the screen but I can't see anything that I am doing. The game is currently stuck like this for me no matter what I do / change. (including restarting and reinstalling).