Built a gaming PC back in 2018 (windows 10, GTX1080, i7, eset security).
For the past year or so it wakes up every now and then and for a few months it started waking up to my logged in desktop screen. Hasnt happened for about a month or so but it still eakes up even with my mouse and keyboard disconnected. I don't do any tormenting or anything sketchy. It's a really clean machine built for gaming, YouTube, office work stuff. I don't visit any "low brow" sites (that's what my tablet (not connected to the PC) is for). It didn't start happening after any specific download that I can remember.
Anyway, I can't find anything relevant online that helps me so I figured I'd ask here if anyone knows what this is about.
Suggest after use disconnect it from the network. Observe if it still wakes up and logged in. If it does not then you can assume that your system is compromise.
There is also this. https://superuser.com/a/1250547, but since you mentioned that it is intermittent then I doubt it might be this.
Another action you could do is change the password of your account. See if it still logged in.