I have a 2015 Sony Bravia with AndroidTV and built-in Chromecast as well as some Google Home speakers. For years I've tried this simple command: "OK Google, Play Stranger Things on Netflix on TV" and for years I would get this annoying response:
"Okay, 'Stranger Things' from Netflix, playing on TV. ... Sorry, I can't play Netflix on AndroidTV yet. Try using your Android TV remote instead."
Apparently this has worked fine with actual Chromecast devices, just not AndroidTV's that have built-in Chromecast. Very annoying and poorly handled, I say.
I made a video and started a thread about this 2 years ago, and others concurred.
I eventually gave up.
Today, on a whim, I tried it again, and, for THE FIRST TIME EVER, it worked! I'm not sure when they (Google? Netflix? Sony?) got around to fixing this, but they did. So I thought I'd share.