Backed the modulator adjustment way out and the 1st to second is really soft. Hangs out in second still though. Looking at the technical data manual page 218. Shifting members are as follows:
1 B2,F
2 B1,B2
3 K1,B2
4 K1,K2
R B3,F

Maybe brake band 1 is getting stuck since all the other shifts seem to work ok?