Nope! It happened with me too. I think it has to do it with the 0.22 update, because prior to that, this didn't happen.
I've reported this issue a day ago, and Nillzz says it has to do with the Moonstone ID being incorrect. Jigglypuff evolves into Wigglytuff via the Moonstone, so it's something about the game checking for the Moonstone ID everytime Jigglypuff levels up. It's weird, but apparently that's how it works. Nillzz has already fixed the ID for the update this Friday (tomorrow).