I have a TiVo 4K stream Android TV and I started messing around with Google home that's when I realize my device shows up in Google home assist and it shows what I'm watching I want to be able to disable that because anybody that has home assist installed on their device and thay are connected to the network they could see whatever im watching and I just don't like that so how could I disable that.
You can turn off Cast media controls notifications on the device itself or under the device in the Google Home app (under recognition and sharing). That will stop the notification from showing up. You can also disable the Chromecast app in settings if you don't want the ability to cast to it at all.