Cruise Control problems of the 2019 Hyundai Tucson

Driving from liberty,mo. To chicago, Smart cruise control set at 70-75 mph, very little traffic, after around 2 1/2 hours of driving ,about 40 miles from hannibal,mo. Car accelerated to 90 mph by itself. Vehicle cruise control would not shut off by cruise button, cancel button, or brake. Got off at first ramp with car running at 90 mph by braking hard. Pulled over and put car in park. Motor surging at high rpm, would not stop running up and down. Cruise indicator lights off. Shut off engine. Called blue link, referred to nearest dealer, no codes showing on car. After half hour restart car, no problems. Checked floor mats and removed. On return trip around 2 1/2 hours from start at around 70-75mph setting, the car accelerated to 90mph by itself, with the Smart cruise control on, no traffic, no floor mats, and turned cruise control off,cruise button, cancel button, brake, but engine kept running at 90 mph. Braked hard, pulled over, engine surging in park. Shut off, waited 1/2 hour, no further problem on way home. Dealership couldn't find any codes or engine or cruise control problems. Noted mats in car, didn't comment when when stated they were informed mats out of car when second occurrence.