I know for a fact that the Shield will work like that with a 2023 LG since it did with mine. I never touched the TV remote. But unfortunately, I don’t have my Shield hooked up right now and can’t find the power supply for it to test right now.
Double check the CEC setting on the Shield, I remember it has detailed CEC settings.
Also check in this thread, maybe someone can help. Sorry I couldn’t help more.
https://troypointinsider.com/t/nvidia-shield-pro-setup/102127