I may have figured it out.
I have an LG TV like the rest of you. Everything is CEC connected, just like everyone else.
I turned off Quick Start. Turn-on-via-WiFi was never on.
My Apple TV is the 4K model.
After watching TV and going to bed, the TV would randomly turn on... and without getting too much into it, I could tell the Apple TV was triggering it via the CEC configuration. I also noticed that when the Apple TV turned on, the remote had to (re)connect... meaning something else was triggering the Apple TV.
While mucking about, I used my other IR remote (Apple TV HD) to operate the Apple TV 4K.
Anyway, I was done watching tv and heading for bed. I turned off the system (hold menu, sleep), and turned off the light.
As the darkness set in, I heard my (somewhat new) Wyze security cam switch its night vision on... and a few seconds later... voila... system back on!
Seems to me, the infrared night vision light was bouncing off a wall and triggers the Apple TV to turn on... and since it wasn’t the Apple remote turning it on, that’s why it would need to (re)connect when I would have to turn the system off again.
Thing is, even after you turn the system back off, it may turn on again, if the infrared light bounces back to the Apple TV... kind of like when you use a mirror to reflect sunlight into someone’s eye.
Now, I haven’t tried it, but a good way to test it, is to put the Apple TV in a shoebox and see if the random turn-on still occurred. Since the new remote is Bluetooth, everything would still be operable.
Anyway, everyone probably has some IR device that is causing the Apple TV 4K to turn back on. So a solution would be to put in inside your AV cabinet, or maybe some black tape in front of the IR sensor of the Apple TV.
