Power loss after engine update ASX

Hello, since last December I drive an ASX with 150hp diesel. I was very pleased with the driving performance until about 2 months ago during the 15,000km inspection of Mitsubishi a motor update was started. Without information on my part, I was only surprised that the passage of the car was significantly worse after the inspection. The turbo uses much later and much more timidly, I have to switch back from the upper gears on slight gradients, but I have to This is now no longer 150Ps, it feels absolutely tangled up. I then approached my workshop, which then informed me about the updated version. I wrote a letter to the workshop, which was forwarded to Mitsubishi. The day before yesterday I took a test ride on this topic together with the master responsible, he confirmed my impression. My question now here in the round: Am I the only one to do this like this? or has anyone else had similar experiences? The update is provided by Mitsubishi and has to be carried out in order not to lose the type-approval, they told me. Only if the performance thus deteriorates, must one accept it?