Mine did that when I upgraded to the IS38 and switched Unitronic tunes to the IS38 file. So weird that while that tune was garbage, their Stage 2 tune for the IS20 was really good and I drove it for 90k+ miles. My only thoughts is maybe the IS38 file takes other parameters into account.Hoon sent me a new tune for my is38 GTI to correct the DV Hang issue where at low speed/ part throttle the DV would hang open bleeding boost and then suddenly shut and the car would surge forward.
This has been a persistent issue, albeit a small one that I've had forever and the previously responses I've gotten from EQT were basically "small turbo problems." I saw that they recently updated their OTS tunes with this improvement and asked for the same improvements to be added to my custom tune. It's perfect now.