Is cloud-sync enabled? This should be the reason.
And 3 red-lights only means: Problems with power-supply. There can be many reasons
I could just unplug my ethernet cable to check, but it's so irrelevant, I won't even bother. Unless cloud-sync is on by default, it's not on.
It takes my Windows PC a lot longer to shut down completely after the monitor goes black, so I'm willing to just wave it off as some sort of MS OS thing.