I caught an articuno via trainerfly in pokemom yellow. I tried to transfer it to Pokemon bank so I could have it in sun, but for some reason, when I go to transfer it, it says that it can't be transferred. This is weird because I don't have this problem with any other Pokemon that I caught via trainerfly. Does anyone know why this is happening?
If none of those possibilities are the case, we can't really figure out what the solution is without more information.