Why won't it let me evolve to jolteon?

So I have tried the cheat by naming them, which worked. The first time.

Stupid ol' me accidentally transferred my jolteon and now the cheat by renaming them doesn't work. And since then, I've evolved eevee 5 times, and haven't gotten jolteon.

Does anyone else know of a way, or why I can't evolve to jolteon?

The renaming easter egg works only once per type.

• Rainer (Vaporeon) x1
• Pyro (Flareon) x1
• Sparky (Jolteon) x1

After that its all random

New information has come to light suggesting that this will work more than once. However to work a second time, you need to do the full set... So you can't just evolve Jolteons...

This Reddit Thread suggests that once you've done a set, you have to do another set, possibly in the same order you did the first set. Possibly with time between evolutions. It may also be that the latest patch has "fixed" this easter egg.