I did some more digging on this last night. I’m more confused now than I was before, and I don’t know what it’s doing.

The arch wiki defines three states, suspend to ram (sleep), suspend to disk(hibernate), and a hybrid suspend(presumably what my steam deck does).

First there is the “turn off the display” behavior. Doing anything brings the monitor back alive and I’m presented with the Lock Screen.

Second is what I believe to be sleep. This happens when I select “suspend” from the menu or leave it alone for a very long time. This mode doesn’t happen soon (maybe at all) if the computer is doing stuff. It appears to be in a lower power state-but I can’t say why I think that (maybe it’s just because the fans aren’t running? I dunno). Wiggling the mouse or doing anything wakes it back up.

Third is another state. It’s just like the above state, except it will not wake up with mouse movement, or clicking keys on a Bluetooth keyboard. I must push a key on the keyboard, the power button, or open the lid. It’s weird because it responds to things other than the power button.

Interestingly, my desktop behaves exactly the same way. But what’s interesting on the desktop is that I can hear a power relay clicking on from this third state. It’s distinctly different than the 2nd state - exhibiting power cutoff, but still responding to the keyboard.

Neither computer enters any other state even after days of being left alone.

So I dunno. Are modes 2 and 3 like two versions of sleep, and hibernate never activates? Or is state three hibernation but it responds to things it shouldn’t?

I have no idea. But now that I’ve played with it some more - I don’t want to say hibernate is working because I don’t know what it’s doing. All I know is that it has the above three behaviors which are consistent with my desktop machine.