No NVIDIA HDMI sound card option

[SillyQuestionAlt]

I'm unable to get HDMI sound output at all. The device doesn't show up in pulse audio, not when i do lspci -H1, and not when I do cat /proc/asound/cards. Is there some driver I forgot to install? I tried doing the basic install ubuntu drivers command, and that didn't install anything useful to my problem. I saw a post late late year about the same issue, has there been any behind-the-scenes updates?
Any tips?

Edit: I've got a link to a ALSA diagnostic, if that would be helpful to post?

[hpfr]

This repo is inactive. See https://reddit.com/r/surfacelinux and https://github.com/linux-surface/linux-surface for the latest updates.