Party Level Gap ?

[プリア@Prier]

From what I've known, at 9 level difference in party will have no penalty for EXP
I've party with my friend as I'm 83 and my friend 74 but it seems that my friend got less EXP than usual (i.e he solo 1.2mil EXP / party 240k EXP) but I still got almost the same EXP compare to solo (reduced a bit due to party)..
So is there any change to party level gap system ? or am I confused about 9 level range (should it be 8) or anything ?

[Beigemidnight]

level difference penalty: 0-5 lvl diffrence - 100% exp, 6-9 lvl - 30% exp, 10+ lvl - 0% exp.
also, experience point bonus: solo play - 1x exp, 2 members party - x1.3 exp, 3 - х1.4, 4 - х1.5, 5 - х1.6, 6 - х1.7, 7 - х2

[プリア@Prier]

So they changed the level range. thank you

[プリア@Prier]

With this, the power level method changed too, right ? I would like to know how it work so that I can level up my mentee fast. Thanks for help anyway.