I did take the car to the dealer who called me and said everything worked fine. Then, when I picked up the car, the voice command didn't work for several tries, but finally did work. I have gotten the the voice commands to work since.
The tech said if the problems continued, he would replace the control module which is the button on the steering
wheel. My own observation is Hyundai buttons seem to be finicky. Push the button the "right" way and all works well, just a bit and no go. I have this issue with the start button for the engine.
I do not have the freeze up issues you mention, at least on an ongoing basis.