Just a little update. I found that after I completely charged the battery, the buttons function properly. However, after a short period of driving with intermittent stops and starts, they come to a halt once again.
I just had a new battery installed in my vehicle since it is parked on my driveway for most of the week while I work from home. After four years of this routine, I had a suspicion that the battery could be deteriorating.
Following the installation of the new battery, the buttons resumed functioning temporarily but have since ceased to operate.
I have scheduled an appointment with my conveniently nearby independent mechanic at the beginning of next year to diagnose the issue with my automobile.
It is important to note that the stop/start function is only operational when the buttons are functioning properly. Everything indicates a potential problem related to electrical or battery malfunction.