Why is my Mac Studio display not going to sleep despite correct settings?

When my Mac Studio was inactive, the screen saver would come on then after two minutes the screen would go blank. Now the screensaver comes on but the display never goes off. I have tried checking with user guide to make sure my settings are correct- and they seem to be. But I can not get the display to go off. Also I have set one of the hot corners to "put display to sleep" but when I put the curser there, the screen goes blank for a few seconds but then comes back on. How can I get the display to sleep when the computer is not in use?

[Re-Titled by Moderator]