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
You have precisely described my experience with my latest laptop. I get probably 4 hours of battery life in this mode. After that my battery is probably at 20% or less which means that when I open the laptop there’s almost nothing I can do with it.
I had to figure out how to re-enable S3 sleep and now I’m struggling with my stupid Wi-Fi adapter which breaks every time I resume from sleep but all I have to do is toggle it and I’m back to running again. After doing this change my battery life in sleep will actually last at least a day now which is massive compared to what it used to be.