High values of Gathering and Perception non-functional

[Haru]

It's not a bug, its designed this way.
Put more money into +GP that way you can pop abilities like truth of the mountains and Kings Yield, as well as some HQ chance boosters.

900GP should about do it for the nodes. (I dont know if its possible).

[Nautix]

The GP cap is ~620 GP, give or take, before food, assuming maximum overmelding with expensive materia at abysmal overmeld success rates (sub-20%.)

Stats only attainable from adding materia to gear or using food doing absolutely nothing is either a bug or needs to be communicated in-game. This could be accomplished by outright removing materia slots from high-end DoL gear (since they do nothing anyway) or capping them (red numbers on the meld screen), neither of which are the case.