We have a Motorola set top box, and it randomly turns our television off.
I know it is caused by the set top box, because we can watch Netflix for hours with the set top box off, and there is no problem. When we use the set top box, the power starts going off.
Everything had worked fine for years until about a week ago when this started. Nothing was changed. All the sleep timers that I can find in the TV config are turned off.
I did a reset of the box using the website, and also unplugged it for 5 minutes or so. Both cases, same result, the TV goes off.
I appreciate any help with this.
As an experiment today, I played two free movies On Demand, about 100 minutes each, and the TV worked like a charm. Then I switched from On Demand to cable TV, and after about 15 minutes the TV turned off. That again casts blame on the cable box as the problem and specifically the cable TV side of it.
FWIW we have also removed the batteries from all the remotes, and the TV still goes off.
We are able to turn it on using the remote, and it doesn't turn itself back on automatically.
Try turning off HDMI control (CEC) if that is an option in your TV menus. Also, if it is a'smart' TV there may be options for network control or connections to alex/google assistent devices - maybe something else is doing it.