I have a (wild) Wurmple on Pokemon Platinum that evolved into a Silcoon which I already had so I used pokesav to turn it back into a Wurmple, resetting its ability, moveset and level. I then changed the IVs until I got a male PID (nature didn't matter) that would evolve into Cascoon and everything came out legal on the legality checker. However, when I levelled the Wurmple up, it evolved not into a Cascoon but a Silcoon. Can someone please help me figure out what went wrong?
The PID I have is 569025011 and the IVs are:
HP: 18
Att: 25
Def: 17
Sp. Att: 28
Sp. Def: 17
Spe: 20