Ccwgtv Ambient Mode not working

Hi All,

I have an issue with all my Chromecast Google TV's where they have stopped going into ambient mode automatically.

I have them set to never switch off and to go into ambient mode after x amount of time. Up.until recently that meant they would switch to ambient and stay on. Now they will switch to ambient but go to sleep anyway after about 10 minutes.

Is anyone else experiencing this?