My parents have 2 smart tv's. One in the living room, on in their bedroom upstairs. Occasionally, they will both turn themselves on at the same time.
I'm unsure what is causing it. I'd say a random signal from a device, but its both tv's at the same time every time it happens. No one has touched a remote when this happens, my mom was in the kitchen one time.
Any ideas?
Just popped in to say sorry about their divorce.
Are there any common devices plugged into them?
Try turning off CEC and see if it stops.
You could start monitoring the web traffic coming from both devices to see what's phoning home. I still have an issue with my Nvidia Shield and the Amazon Prime app waking my TV.
My Sony Tv has also been doing this lately. Is yours Sony?
Maybe a power surge? Small enough that nothing else detects is but big enough for the tv's to function this way. Same make and model?