Know how to fix an intermittent performance hesitation on new Avalon Limited?

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2016 Toyota Avalon Limited - New 4,700 miles. When accelerating from a stop or slow roll, vehicle hesitates 1-3 seconds, when slightly stepping on gas to go. This hesitation has happened at least 1/2 dozen times, and has put driver and occupants in harms way. Took it to dealer, but they were unable to reproduce issue, and thus could not resolve the problem. Dealer said, they had tested it diagnostically and by driving vehicle. Dealer had no answer for the problem. Dealer said if it happens again, bring it back in for further testing. Am thinking I soon could be calling the dealer from the hospital, or from 6ft under ground. (BTW, it's been in the high 90's temperature wise; I read online that it could possibly be related to a heat build up under the hood...Mentioned it to the dealer, but they didn't try to simulate the hot conditions. Any suggestions?