Hello,
I have encountered a problem only with Red and Blue save files where the two PC boxes after the last box I use are filled up by the same Pokemon each time all captured by a trainer called Ryan that I have never interacted with before. It also replaces the last Pokemon of my PC box (which was a Snorlax), with another Pokemon of my party (Garaydos). I've also had the MISSINGNO Pokemon appear in my box without me adding it when I load up the save file I edited. Does anyone know about this issue with the original Pokemon games and PKHeX? My PC box ends at box 3 with the last Pokemon being incorrect with the previous Pokemon and the Pokemon from the previous boxes being correct.