I checked on my 2019 and mine beeps every time you press the seat heater button. I checked my settings and "Audible Touch Feedback" is turned on: maybe that's the difference. Still, it only beeps once each time you press it so unless you keep track in your mind of what setting you are on, you wouldn't know when it is off. First beep is high heat, second is medium, third is low, and fourth is off. It would be ideal if there were two beeps when it goes from low to off but unfortunately it doesn't.
Also, contrary to what I said above, I noticed the dots on the indicators are red which means people who are red/green color blind (the most common color blindness) will not be able to see the dots. I tried the other themes like Sunset Orange to see if the color of the dots would change but I was in the garage and I don't think the theme change shows when the headlights are on. Best solution I can see is to turn on the Audible Touch Feedback and remember where you are. If you prefer full heat for example, press it once and remember that to turn it off from there, you need to tap the button 3 more times (3 beeps). Etc.