I have a MacStudio display into which I plug in either a MacBook M2 Pro on a MacBook M1 Air. When either is plugged in I just put the machine to sleep when I am finished using it. However in the morning the MacBook is still sleeping but the fans in the display are on. No applications are open and wake for network access is off. Whether the fans are running all night,I don't know. I am curious why this is happening. If I shut the MacBook down as far as I can tell this does not happen.