NHTSA Complaint #11418186 — 2015 HYUNDAI SONATA

I'm really at wit's end with what is going on with my car. My car is currently at 104K, its a 2015 Hyundai Sonata Sport. A beautiful car with an abundance of serious issues. I've had trouble with my car accelerating for over a month and I've taken it to at least 5 mechanics who have troubled shooted with no success to fixing the issue. The problem: my car hesitates significantly when accelerating and sometimes when it's can't shift gears and I'm easing my foot on and off the gas pedal, it begins to shake while attempting to accelerate. I try not to put the car in sport mode but sometimes this mode is what helps the car shift gears but I don't think this good for the car. So far I've tried changing all of my spark plugs and coils replaced, fuel injectors cleaned (dealership), transmission fluid changed and ECM updated (dealership). Also, the Hyundai dealership diagnosed the issues as an engine problem (intake exhaust and timing chain + tensioner) --- cost of all these things almost $4000!! I just don't understand why the check engine light is not coming on -- which is hinting at the local mechanics that it might be a transmission based issue. No the check engine light has not come on but the car drives really poorly. I'm taking it to a transmission shop and hopefully going to get some answers as to what is going on. This issue is absolutely frustrating and now I'm just looking for real direction by waiting to see if the engine light will come one and throw a code