It used to be simple, either using the volume buttons or the circular slider of the device in the Google Home App. Now, none works. I have a cryptic incomplete pop-up message saying "to control this device volume with your phone..." and that's all.
Is it too much to ask to use my Google phone to control my Google TV?
Google Home and Google TV apps both have remote controls for the CCwGTV. If you install them (at least the Google TV app), you can have a quick tile to launch the remote.
Found it:
Had to change volume controls in the Goggle TV settings from my TV to Chromecast
If you Google TV is setup to control volume via IR, then it's not going to work. The "dongle" isn't going to send IR to your TV/Receiver.
HDMI-CEC works fine, but you don't get % because that's not how CEC works. It only sends commands to the TV/Receiver. It doesn't get a value back. You can do the dynamic volume, but generally that's not good with a receiver since it'll just be PCM audio.
Patent issues with Sonos. They had to remove it within Android 12. But Google is working it, and it should be in 12L when it gets released.