I just powered on my Pi to double check what you asked me to, Audio is set to HDMI in raspi-config and alsamixer shows a volume level of 100, but during boot up I noticed I had sound again.
The only change was a night of sleep, doubt it was that, and me swapping hdmi cables from my pi to my PS4 and back.
My tv is pretty old, so maybe it is messing up the edid?
I did make changes in config.txt that should force it to recognize the hdmi, but that didn't seem to help before.