there have already been many questions about pairing the sound from the chromecast Ultra to Nest Audio speakers. Surprisingly, this works fine with the "ARD Mediathek" app. as follows: while using my Android device (Pixel 3xl) as remote control, chromecast is sending video- and audio signal to the TV. Next I open the Google Home App "Media" and can select Nest Audi additionally to TV(chromecast). Picture and sound then work without delay.
Why does it work with the "ARD Mediathek" app but the other streaming apps can't
Hey there Seinist,
Thank you for visiting the Chromecast Community! Since this thread hasn't had activity in a while, we're going to close it to keep content fresh. We hope you were able to get the help you need, but if you're still having issues, please note that the setup you are attempting isn't technically supported. If this is something you'd like to see in the future, please feel free to submit feedback via the Google Home app.
If you have any more questions, feel free to create a new thread, and provide as many details as possible so that others can lend a hand. Hope this helps!