Ignition Switch problems of the 2011 Chevrolet Silverado

While driving in traffic the Silverado's, engine, power steer and power brakes shutdown completely. After the vehicle stopped. The automatic transmission was placed in park and the truck restarted normally. I took the truck to the dealer and they found no problem or code. The same event happened again about 3 months later while I was on an interstate driving about 70 mph. The I was able to bring the vehicle to a stop in the side of the road I then placed the transmission in park and the vehicle started normally. I believe ther is an issue with the ignition switch.