Very sick hyundai santa fe - heat caused

when the heat gets over 105 degrees my sante fe wants to stall and hesitate with I stop at a light or stop sign. The car has to be driven for over 15 minutes to duplicate this problem. The dealers mechanics never drive it long enough to duplicate the problem. I live in las vegas and it gets over 105 alot! What can this be and why does it only manifest itself when it’s extremely hot? Car has 92000 miles and has the v6 3.5 l engine -

Drive the car 14 minutes and 55 seconds on a day over 105 degrees into the dealership and leave it running.