See Wake Source in Windows 10  

I'm glad you got it sorted realista87. Thank you for posting back with your findings.

Just leaving this as useful reference for future readers:

My 'lastwake' response was simply 'Power Button'. This wasn't very helpful as i wasn't anywhere near the thing when my PC woke up twenty seconds after putting it to Sleep.

Googling came up with a few helpful responses. I disabled 'Allow this device to wake the computer' for my Network Adapter. (Device Manager - Network adapters - Power Management Tab).

Allow or Prevent Devices to Wake Computer in Windows 10​

Problem fixed.

hdmi said:

In Step 3 under Option Two, if I check the checkbox for Kernel-Power instead of Power-Troubleshooter, then I can see that Event ID 507 is what causes my laptop to wake itself up inadvertently from Connected Standby when Modern Standby was enabled. I.e., I had removed the Dword registry value named PlatformAoAcOverride from the registry, and I rebooted after. Next, I ran the powercfg a command to verify that Modern Standby, or S0 Low Power Idle was supported by the system again. It was. So then I put the laptop to sleep to see if it would wake itself up inadvertently, which turned out that it did. (Just like it always does, if Modern Standby is enabled on it.) I am running on Windows 10 version 20H2.

What this showed me is that, in its current form, Step 3 under Option Two may not necessarily always be adequate, as this tutorial wasn't helping me to see the Wake Source until finally, at very long last, I had figured this out... eventually.

Thank you. I've updated option 2 to add this to help others with the same issue.

Brink,

Perhaps you would like to add a note to your reference to EventID 507 that EventID 506 is the event recorded for entry to S0 Connected & Disconnected standby. Or perhaps you wouldn't.

Entry to S0 Connected & Disconnected standby
Log - System
Source - Kernel power
EventID - 506

Exit from S0 Connected & Disconnected standby
Log - System
Source - Kernel power
EventID - 507

In my post #40 Event viewer, Custom view definition: Power - Sleep-Hibernate-S0 transitions there are some further details together with a Custom view definition that captures entering & leaving S0, S3 & Hibernation. I combined them into a single Custom view so I can use it without any alteration on all my proper computers as well as on my S0 computer.

All the best,
Denis