DOWNHILL BUTTON AND BREAK LIGHT ABRUTHLY CAME ON SAME TIME

My 2021 Tucson red brake light along with the downhill button red/orange ( not sure which color )button abruptly just came on as I was starting to drive, it made a loud clunk noise then stop I pushed the gas again and made another clunk noise and stop again. I turned off the car and turned it back on and the car was fine. I took the car into the shop and they found nothing, the sudden stop the car made really jerked me so glad I was not driving fast. The sound was similar to a wrench being thrown under the breaks that's how I can explain how the clunking noise was.