Diesel owners question

[Jabba2432]

Hey guys I have a 2011 X5 35d 91000k miles. Second owner and have owned the car for about 4 years now with no major issues. Took it to the dealership for air back and driveshaft recall work. Since getting it back it has been a nightmare. They suggested I do a front and rear differential and other maintenance based items. Funny thing is when I got the car back I got an error for chassis error dsc and x drive malfunction error. I usually get my work done at an indy but since moving its over an hour to get there and would be without a car. So long story short after having them address this and another issue which happened to be nox sensors which they fixed for free since bmw has extended the warranty I have the car back. The question I have for you guys is that is it normal when you are breaking coming to a stop light or slowing down that your rpms jump when it gets close to 1k then settles then jumps again?

TIA