Your 2015 Sedona may have the same V6 as we get in the Sorento but it does not have the 8 speed transmission which is when this problem started occurring. I think everyone with a 2016-2018 V6 Sorento with the 6 speed is happy with the performance and doesn't get any of these hesitation issues. I also suspect that the tuning for the V6 has changed over the years and further suspect it's different for South Africa than the US.Welcome to the forum and to the V6 problem club🤣. Thank you for the information on the possible solution with the ECM. After the transmission thud on between gears (1 & 2) and cruise 6, I've had the engine stall / loose power a couple of times. Battery is new and alternator working perfectly. If it occurs immediately after leaving home I stop and restart the engine a minute later which solves the problem for a day. I then got an ODB2 scanner to check and clear these ECM errors. I will request the dealer to check the ECM at the next annual service in December. Thank you.