Audio spontaneously dead

I was playing streaming video on an external display connected via HDMI to Thinkpad X1, listening via Thinkpad’s headphone jack. Left the room for around and hour, returned, and there was no audio. I disconnected HDMI, rebooted, ran software update. Still nothing.

Tried manually restarting wireplumber pipewire pipewire-pulse. Still nothing. According to the Volume widget in the system tray, there should be audio going out, but it’s not. (And I don’t have it muted by accident either lol.)

Edit: Strange stuff everyone! In System Settings > Audio, I changed the “Profile” to “Play HiFi quality Music.” VOILA. I switched it back to “Pro Audio” and audio resumed.

What is going on here?

This sounds like a power management glitch. Just rebooting without powering down might not fully reset power saving while just changing settings
can “wake up” sleeping devices.