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
I had something similar a while back, where it was waking up from sleep for no reason. I can’t remember the exact reason, but it had to do with a hardware being allowed to wake the device. I disabled it from being able to wake the machine and haven’t had a problem again. You can use the cmd to find which device woke your pc.
You’re right, it could be a setting in Windows or perhaps the BIOS. I know there is often a ‘wake on LAN’ BIOS setting…