OK, so, the other day, I EV trained a Clauncher, and yesterday, I used aforementioned Clauncher to spread Pokérus to a Vivillon, which I also EV trained. The date rolled over, with both of them in my party, and you know how that cures Pokérus? Well, I'm looking, and not only do neither Clauncher nor Vivillon have Pokérus anymore... but it's looking as though they had never had Pokérus to begin with. There's no little pink face next to the Kalos-born pentagon, there's no bar next to the types that indicates that they have Pokérus, nothing. And I know they had Pokérus because of how I EV trained them... I'm pretty sure this isn't a normal situation, does anyone have any idea what's going on here?
This probably doesn't help, by the way, but just in case it does, the Vivillon is Monsoon Pattern.