I got the same issue months ago, with Mint. I have a script to switch audio outputs, and it stopped working after... apt upgrade! Apparently what used to be called "hdmi-stereo" is now "hdmi-stereo-extra1", no idea why.
In the case of my script, once I got what was going on, I solved it with a simple "if" statement:
if [[ $(pactl list sinks | grep extra) == "" ]]
then declare -g mainProfile="hdmi-stereo"
else declare -g mainProfile="hdmi-stereo-extra1"
fi
(My system uses pulseaudio. Don't ask me why. I'm not touching it with a 3m pole.)