I have a network-wide pi hole and I noticed that it requested activity.windows.com, a url blocked by my pi hole, even while my pc is suspended. I pinged 10.0.0.217 and it is currently unreachable. So, somehow, windows pc’s turn on networking, phones home, and turns off even while suspended.
Creepy behavior
My phone is never plugged into my computer and I don’t have any service like that running that I know of.
It could be OneDrive (though I don’t use it at all) or even the ghost of the Explorer iCloud plugin.