frank bessler

Couldn't find where to post this problem. 2018 chevy 3500 dually. 60,000 miles. Took to dealer and was told they couldn't find anything wrong. Right turn camera works under 70 degrees but intermitly above 70 degrees. Screen goes black and sometime the left camera goes black but resets after you turn the key off for a few minutes then both cameras work. Also get app failure screen but no codes present. So I'm look for ideas where to look Thanks frank