Our 2016 Santa Fe Sport started having intermittent rough starts several months ago at 103,000 miles, no codes or check engine lights yet. When this happens, it takes a little while to start, idles really rough and the RPM dial shows no rpm's. Then shut it off, and it starts fine with the RPM dial working. Our dealership said it needed a new battery, which made sense at the time since the car is 6 years old. But they said they couldn't replicate our problem. Also, now and then the car seems to hesitate a little at 70+ mph. Any ideas or suggestions would be helpful. We've never had any issues before this one, we really like the car but don't want to sink a lot of $$ trying to track down the problem.