I have a first gen fire tv (not the stick) and it keeps waking my Samsung TV.
I have disabled CEC/Anynet on both the TV and the Fire TV. But it still wakes my TV.
I even purchased a CEC blocker that blocks pin 13. It seems to work too, because when I enable CEC/Anynet the signal is disabled.
But still, my TV gets turned on randomly. It is not even turned on properly. The TV clicks, the screen goes on and a few seconds later it turns itself off again.
I disconnected all other devices, so all I can see as a potential cause is still the Fire TV