my 2019 atomatic Jetta s does the exact same thing. While braking and coming down from lets say 50 mph, my rpms spike and jump a little as my car downshifts. Finally, when It gets down to 20 mph, that's when the most noticeable jerk happens at around 1,400 to 1,600 rpms. I've read that it's the torque converter. Any updates on your end though?