[Arch] Alsa/Pulseaudio sound issue - Analogue sound card disabled

Hello. This is my first time completing an Arch installation, and I'm having a strange issue with my system's sound cards. By default, the system has set the output audio to my HDMI monitor (Nvidia HDA). I am trying to instead set the output to my motherboard's analogue audio which is 'Family 17h (Models 00h-0fh) HD Audio Controller' (AMD Ryzen chipset). Unfortunately, according to Pulsemixer, the only option for the card is "Off" or "Default / Off". There isn't much documentation about this issue online. Moving applications from the HDMI audio source to the Family 17h source does not yield any results. I've also tried installing various Alsa firmware to no avail. Alsamixer sees the sound card just fine, however.

I should also mention, when I was tweaking my motherboard's BIOS, enabling CSM support so I could dual boot an older operating system, the audio output changed from my main HDMI monitor to my secondary DisplayPort monitor, though still under the 'HDMI' label. I'm not sure why this happened.

Any ideas on what I could do? Thanks.