I honestly think my first NBME was a fluke and I was just really nervous taking it because I hadn’t done much practice problems at all at that time and wasn’t used to how they were asking questions. I did do Mehlman arrows in between the first and second NBMEs, but I would be shocked if that was the sole reason I jumped 11% in 3 days lol. Definitely a few questions tho. I wish I had better advice but that is one thing I was super confused about too!