note that it won't report reasons the machine was woken from hibernate, since hibernate isn't a sleep state.

also, run the command as an administrator. not just using an account that is an administrator. use an elevated cmd prompt or PowerShell window.

if you're doing all that, idk what's going on.

You can, however, see what devices are capable of waking your machine, and then disable them, by using the commands in my other comment: https://news.ycombinator.com/item?id=28647492

¯\_(ツ)_/¯ No hibernation, yes admin, yes elevated prompt, nada. Disabling devices has never worked for me either, again I'm legitimately surprised that these things have ever worked for anyone since it's never had any effect whenever I've tried it.

check the tasks in Task Scheduler, too. those can also wake a PC from sleep.

I wish that were true! I'd love to know how to do that one too since back in Windows 7 Foobar2k was able to wake my PC from sleep and play my music as an alarm, and this functionality has not worked for me since then.

For a device to be able to wake a Windows system, it has to be allowed both in the BIOS and also in Windows's device manager (In the "power management" tab on a device, the checkbox on "Allow this device to wake the computer" has to be set/unset). It is available only on certain classes of devices.

Also what you are referring to as an application's capability (Foobar...) to wake a computer (from sleep or hibernation only) it most probably has to do with setting an RTC (real-time clock) alarm and the computer being allowed to resume from such an event. Again this is also a setting which can be disabled in most BIOS configurations and yours probably is. By the way, Windows' task scheduler exposes this option to everyone so you can set your computer to wake up and run some script and then sleep again (I used to do this all the time ages ago for night downloads, etc.)

So, there are a series of switches (in BIOS and in windows device manager) that all have to be set/unset, for a computer to resume from some event;

It only works for the most basic mouse/keyboard scenarios in my experience