Rerolling PID changes Nature in later pkhex distributions

[Aurorans]

Hello! I've been noticing in all games dealing with PKHEX on later versions of PKHEX, rerolling PID changes the Nature of the pokemon.

 

Why was this implemented? Especially for gens 1-4?

[BlackShark]

Before Gen 5 the nature was not stored in the Pokemon data, it was determined by the PID. So it's technically impossible to only change one of them.

[Atrius97]

This is a feature, not a bug. Also, Gen 1/2 have no personality value, so please don't report issues that don't actually exist for a given generation. This only happens for Pokémon generated in Gen 3 and 4.