Speaker group does not work with Chromecast

[TempestTpot]

I have a Chromecast attached to a dumb TV. I have two Google nest Audio speakers. I would like to use them for stereo playback.  This appears to work just fine with the YouTube Music app when I cast from my phone. There doesn't appear to be the same functionality from the regular YouTube app. What gives?

[Byteguy]

Unfortunately, Speaker Groups only work when you are casting audio-only sources (like YouTube Music and Spotify).   They do not work on any mixed audio/video sources (like YouTube and Netflix).

That's how they have always been.

You can tell Google what you would like by using the "Send Feedback" option:
https://support.google.com/chromecast/answer/6292231

Google doesn't read every post in this forum but they do read and track all the feedback they receive that way. Just so you know, they won't respond directly to feedback so don't ask them any questions.