my wife drives a 2016 hyundai santa fe (7 passenger). It has 68000 on it. We bought is used with 1300 miles. About a year ago it started to hesitate when it shifted from low gear to high gear. the hesitation does not happen all the time. It just happens sometimes. The hesitation became progressively worse to the point it at times almost stalls out. In addition, at times a loud bang would happen with the hesitation. The problem is that no service station can replicate the problem. We have had a fuel flush done and we have had the transmission fluid changed. It seems like it could be transmission related but the Hyundai dealer said that our model has not had transmission issues. We are planning to take a road trip down south this summer and would like to have this issue resolved before we leave. In your opinion what steps should be take to get this problem fixed.