New Apple TV 4K remote microphone does not work in any of the apps. Language is set to US English
New Apple TV 4K Remote Microphone does not work
Apple TV 4K, tvOS 15
Question marked as
Siri functionality on Apple TV is supported for 24 countries and just for the main languages of those countries. Setting the language to English in countries with other main languages, will not work.
Use Siri on your Apple TV - Apple Support
For use, you have to keep pressing down the Mic button while speaking commands.
Dictation is available for more regions. That is available when the focus is on a text input field. Use Siri dictation on Apple TV - Apple Support