I have a ROG Strix Hero II laptop, about a year old. FOr the first time I tried plugging it into my TV via HDMI, but there's no audio.
I went to change the audio to HDMI and it's not listed. The only audio device listed is the realtek speakers.
I reinstalled the nVidia drivers (clean install) but no change.
I checked the device manager and there's no device showing for nVidia audio. I checked audio devices and nothing is listed, disabled, hidden, or otherwise.
I have the latest drivers from nVidia and GeForce experience runs fine. Everything else works.
EXCEPT - nVidia control panel won't run. It's in the start menu, but I select it and nothing happens.
I googled for solutions but nothing I found works, or seems strictly relevant - they all assume you at least have the device listed somewhere, or just suggest reinstalling.
So I decided to try installing the version from the ASUS website for my specific model, which says it's Version V220.127.116.116 2020/05/25. When I ran it, it complained "The standard NVIDIA graphics driver is not compatible with this version of Windows." and suggests installing it via GeForce experience (which is what I already have). So no joy there either.