Just pushed update 1.0.4 which has a bit of a bandaid on this until I can figure out the root of the issue. If you go into settings, turn off fullscreen mode, and then restart the game, you should be able to play with audio over HDMI. You can manually stretch the game window to your screen size. Sorry it's not ideal, you'll probably still see the window chrome and taskbar, but I'll keep trying to figure out what's going on with Game Maker and these audio drivers. At the very least, I might try to figure out how to do a "windowed fullscreen" mode to circumvent this issue.