XC60 BJ2011 kicks and nobody finds anything. 🙁

Hello forum members, maybe you can help me, because our car (XC60 D3 163PS 2011) has had the problem for about 1.5 years that it “jumps”. Up to 30 km/h you don’t notice anything about it, especially about the 50 km/h, if you give little gas, then it jerks. The engine itself, it seems to us, runs at every speed quite normal, as soon as you decouple the car during the ride, it also runs calmly, as soon as you switch again to “D The strange thing about it is that there is one of about 30 rides, where he doesn’t have the problem, then he runs quite quietly. I was already in two workshops, among other things with Volvo itself but you can’t find anything. At Volvo they said that you could change the AGR valve and cooler at a flat rate. But 1200 euros and then is not even sure that it will fix the cause? Of course, that’s all very awkward. Greetings, because except for this problem (and drive El. tailgate) we are fully satisfied with the car. Does anyone have tips? Thank you very much Best regards Markus