Apple TV 4K 3rd gen 128 gb

Hi Alex_2023,

Thanks for posting in Apple Support Communities.

We understand that you're unable to use Siri Remote with your receiver after upgrading Apple TV. You can set this up to work with your receiver.

"Use the Siri Remote to control the volume of your TV or receiver

1. Open Settings  on Apple TV.
2. Go to Remotes and Devices > Volume Control and choose Auto.
3. Note: These settings may not work with all devices. For more information, see the Apple Support article Control your TV or receiver with your Siri Remote or Apple TV Remote."

These steps are found in Control your TV and volume with the Siri Remote - Apple Support.

Regards.

Thanks for replying, Alex_2023, and that additional info, it really helps! Let's have you restart your new Apple TV remote:

"Restart your remote

If your remote still isn't working as expected, try restarting your remote.

1. Press and hold the TV/Control Center button  and the Volume Down button  at the same time. Hold the buttons down for about 5 seconds, or until the status light on your Apple TV turns off and on again.  
2. Release the buttons. Then wait 5 to 10 seconds for a Connection Lost notification to appear on your TV screen.
3. Wait while your remote restarts. When the Connected notification appears, you can use your remote."

And those steps are from If your Siri Remote or Apple TV Remote isn't working - Apple Support

If you are still having this issue, please contact Apple directly for further investigation: Get Support

Have a great day and thanks for using the Apple Support Communities!

Hi Alex_2023,

Contacting Apple Support is the best path forward to resolve this issue. They will be best equipped to investigate this further for you:

Contact - Official Apple Support

Cheers!