I have my mi box set to never sleep and I set up daydream, but when I try to use it the first time each day(after quite a few hours if not using it), it won't turn on and I can't control it with HDMI cec so I have to unplug and plug in my mi box to get it to turn on again. It also won't allow me to cast anything to it in this state. I have lost my original mi box remote so I can't use that to control it. Is there any way I can set the mi box to not go to sleep or does anyone know the ir codes for the mi box so I can set it to directly turn the mi box on with my remote?
I've noticed recently that my Mi Box power is now "linked" to my TV. When I turn off my TV, my Mi Box goes to sleep. And when I turn my TV on, my Mi Box wakes up. Sometimes, my Mi Box won't wake up when I start my TV. I simply turn the TV off and back on and it eventually wakes up.
Not sure if this helps with your issue, but I figure I'd give my perspective. Good luck.