Got my console set to instant on mode and can switch it off with the voice command. And if I go back to it within an hour or so, the power brick light is still white and I can switch it on as normal.
However, if I leave it for a few hours or overnight, the power brick light will have turned orange and I have to switch on the console using the power button on the front. The console then does a full power up with the green Xbox One screen etc.
When I'm using the console it stays switched on and I have no issues at all so I'm puzzled. I've just done a hard reset to see how it goes, but I'm not hopeful.
I tried contacting MS support via the online chat option. But they just kept saying an orange light was normal and it was all normal behavior, which it obviously isn't! I just couldn't get them to understand and they just pointed me to the MS page showing what the power brick lights meant :( Not good! Thanks