Why does my Dell Latitude 5580 wake every day at 06:00?

Question

I'm running Win10 on a Dell Latitude 5580 laptop, and I habitually hibernate it when not in use.

• If the laptop is not connected to the Dell dock then it reliably stays hibernated.
• If the laptop is connected to the Dell dock then it wakes itself up from hibernation, every day, at exactly 06:00. 🤬 I can then easily put it back to hibernation, and it stays that way until 06:00 the next day, or until I turn it on manually before then.

I've checked all Windows settings I can think of, and I've checked all BIOS settings, but I can't figure out why this happens. There are no scheduled tasks. There is no special Dell software installed, and I don't think that the dock itself has anything like a BIOS or other settings -- it's just a box with an USB-C cable. I have 2 monitors and a wireless Logitech keyboard attached by Unifying receiver, nothing else. There are no pets that could trample on the keyboard or push any buttons. There is no wake-on-LAN, either.

How do I turn that off?

Edit: I found lots more in the Task Scheduler but it looks like they are all either disabled or at least set to not "wake the computer to run this task." See third screenshot for example. Fuck, there are so many! If only there'd be a way to programmatically go through that entire tree! I probably shouldn't simply disable it all but so much of it looks like corpo stuff that is definitely irrelevant for a home machine.

Task Scheduler:

Device Manager:

Nasty large tree of scheduled tasks:

Answer 1

I had several computers at the office that used to wake themselves from hibernation at exact hours. Sometimes when I work on another PC in the same room, and there is no one else, I hear the machine wake. Notably, each one did it at an exact time of the day, no matter if it was workday or weekend. I was curious to find out the reason. (1) It might be a Task Scheduler task - that has been set to execute at an exact hour. Inside "Settings => Conditions" for this exact task, it has a checkmark at "Wake the computer to execute this task". It might be difficult to find, out of many Scheduled tasks - which one has this checkmark. But it might help. (2) There is a setting of the network card that will prevent another device on the network to wake the machine sending a simple ping to it. The "Magic Packet" is defined more precisely with a port, MAC-address and IP.

Answer 2

If the computer has not gone back to sleep, the command powercfg /LASTWAKE will (usually) show the reason for waking up.

This doesn't always work; sometimes there's no reason given, and sometimes the computer has gone back to sleep and then this command would report power button instead. But normally this helps with narrowing down the root cause.

In my case it was a backup task, which I would not have been able to find in the many hundreds of entries in the Task Scheduler which doesn't even have a search function!