some kind of pressure issue propobbly. I'm fixing mine next week, It has pressure accumulator problem(indy told me) when chaning from 1st to 2nd gear, there is slight 3 secconds delay, where it Revs up as if it was in neutral in that time. Definetly get it fixed. 37k miles is sooo low, It's a brand new car. with new tranny it will run forever.
As for last step braking that tranny is very easy as well. do brake +gas in first gear few times it brake something in tranny for sure.
Wish you Best luck with that problem.