why when i switch to a dol am i not at full gp its dumb

[Sove92]

Actually when you switch to -any DoW/DoM- job from DoL/DoH, it starts you off at 0 MP
When you switch to -any- DoL class from DoW/DoM it starts you off at 400 GP.

The difference is?

The difference is that DoW/DoM have a base GP of 400, something that was added in 2.15

The following changes have been made to gathering points (GP).
Players will now also accumulate GP when playing as a Disciple of War, Magic, the Hand.
GP will no longer reset when changing to a non-gathering class.