I was on my lvl 14 thief and decided to job advance. Upon doing that, I realized that I had only received 1 SP from the leader (should've received 13 if my calculations are correct). I'm guessing this is a bug and not intended.
Actually I believe back in the day, it was the case. You would receive only 1 SP for job advancing and that was only it. It is working as intended, not sure if MapleRoyal will have it differently but I remember having to restart a few time new characters on GMS because of that.
I got level 9 on a HS mule I was creating but got the SP from the earlier level in the old source. Edit: Sila beat me to it