Nicknames don't work (in some cases)

[usersaurus]

I'm having a weird bug when trying to put nicknames on pokemons using the !tradeSV command. I'm getting a Ditto army with different nicknames based on the IVs they have. I did:

• Estupenditto (perfect IV): no issue
• Flojitto (0 IV attack): no issue
• Lentitto (0 IV speed): nickname is not used and the received poke is called Ditto

I tried several times and always had the same issue, so looks like there's something odd with all or part of that name.