I have a Sony Bravia TV with a small microphone plugged in a USB port. A few days ago I was watching YouTube and in the video someone said "Okay Google" and Google Assistant launched, I didn't know I could actually activate it this way. But not all the normal Google Assistant commands works, I thaught changing the language from en_UK to en_US would work, and it did give me all the Google Assistant commands but I lost the Okay Google hotword. Changing the language back to en_UK didn't work.
Does saying Okay Google active Google Assistant for any of you with Android TV? And maybe someone knows how I can fix it?
If there isn't a setting on your TV, but it is linked to your Google account, you may be able to change its settings from the Google Home app or the Assistant settings on your phone. Tapping the blue spacebarish/close bracket fallen over icon on the Assistant popup on brings up a screen whose overflow (three dot/menu button depending on the device) menu has the settings option.
Some devices expose lots of settings through that interface, others not so much if at all.