I have a 2016 Samsung TV and just got a new Chromecast. When I power on the TV there is a 95% chance that Samsung's stupid TV Plus channel will start first and either stay on the screen or take a few seconds to disappear.
Not sure if this is due to how the Chromecast powers on or whatever, anyone else have this issue? Can't find a way to disable TV Plus as I don't need it. The Chromecast should keep a little power going when off so the input stays active on the TV, this should fix the problem. My old cable set top box did this, more of a standby mode rather than off completely.
the TV isnt recognizing the CCwGTV as a HDMI input so its powering up to its default. I had this happening with my Hisense tv - roku set up. I unplugged everything and repeated the set up procedure step by step and now everything is fine.
So in short the problem can be a little as a low power source like a old surge plate or extension cord and the sequence of connecting the power cord and the device to the TV..