2008 Pontiac GP cruise control problem

I have a 2008 Pontiac Grand Prix, v6 3.8l, and have an intermittent problem with the curise control. Every once in a while, when I either hit the decel button, or the accel button, the cruise control just shuts off. It only shuts off when I hit either of the two buttons. It won’t do it on command. It seems to be totally random. The cruise works fine and never shuts off if I’m not hitting one of the buttons. 98% of the time it will speed up or slow down just fine. I’ve use the cruise every day to and from work. I tried to wiggle the stalk, bump the brake pedal, and nothing else will cause the cruise to turn off except the random time when I hit the excel or decel. Any ideas? My local dealership has no idea because nothing shows up on the computer codes, and it never does it when they drive the car. It’s very random and can go days without acting up.

Be thankful it works at all…