My experience - smart TVs tend to be really bad at CEC during power on, because they are booting while the other device is asking them to execute commands like

My experience - smart TVs tend to be really bad at CEC during power on, because they are booting while the other device is asking them to execute commands like switching input. I usually set the TV to 'last input on boot' if such a setting exists. I've noticed the Apple TV will ask the TV to switch input via CEC on pretty much any button press, which is non-ideal but is a decent enough workaround.