PC waking from sleep for unknown reason

I found that it was the "Allow Wake Timers" detailed here.

This has worked for me so far. Go to:

Control Panel\Hardware and Sound\Power Options\Edit Plan Settings

Click "Change advanced power settings"

Go to "Sleep->Allow wake timers" and change the setting to Disable.

And also from here.

Go to Task Scheduler

Find NT TASK\Microsoft\Windows\UpdateOrchestrator\Reboot

Its actually just named Reboot but you have to go inside those folders

Right Click > Properties > Conditions

Uncheck Wake the computer to run this task

The issue was caused by TeamViewer, it creates wake timers that are somehow ran(?) even though wake timers are disabled. Even shutting down TeamViewer doesn't solve the issue for me. But uninstalling TeamViewer resolved the issue.

Another approach is to see which devices are able to wake up the computer :

powercfg -devicequery wake_armed

And then, try to deactivate this device related privilege in devmgmt.msc