I think I may have to abandon Raspberry Pi as the platform for my little home media center project.
At this point I've tried two Raspberry Pis, swapped out the power supply for a better one, and swapped out the KVM switch for a powered one. I cannot get the PiOS to recognize the HDMI output as a viable audio output target. It can see the card, it can see it has audio hardware, but it only allows for headphone jack as an output target and I can't compel it to believe otherwise. Googling suggests I'm failing an EDID handshake, but the Chromecast attached to the same KVM navigates this issue with aplomb, so...
Feels bad solving what is clearly a software problem via hardware, but if anyone has a recommendation for a low-power Linux box that will do Wifi and proper HDMI-out-including-audio to a TV, that's really all I need.