Can't get my Mac Pro to sleep in OS 13

I have been searching online for hours. I'm coming here as a last resort. I don't know why this is so hard. It used to be easy.

I have learned that many people think their Mac is sleeping when it's NOT. When you do various sleep settings with OS 13, they primarily deal with the Display, not the Mac Pro. Even following Apple's guidelines and procedures, they talk about the Display. My UPS has Watt meter on it. I can tell at a glance if the Mac Pro has really gone to sleep. The only way I can get the Mac Pro to go to sleep, is to do it manually.

For some strange reason, it appears that the key setting is found under "Displays" > Advanced. There I have found a switch "Prevent automatic sleeping, when display is off". I have this turned off. Nevertheless, I can tell by my Watt meter that my Mac does not go to sleep.

I had no difficulties with sleep in (the vastly superior) earlier versions of Settings.