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.