Is green mode supposed to be jittery?

Test drove my first mini today! It's a 2018 cooper s, and the green mode seemed to be really...jittery. I switched it over to sport mode and that seemed to help, but I'm wondering if that's a typical problem to have in green mode or if it's something to be wary about.

Edit: it has 101k miles, so could it maybe be a problem connected to the transmission?