Single post in Evolving Feebas

Hello all~ I have just a quick question. On the Pokedex, it said to evolve Feebas, I just need to have high beauty. Well, I just maxed out the "Sheen" stats on the Contest section in beauty. I basically fed all blue pokeblocks derived from Chesto and Oran berries, however, I do not have the option of evolving my max beauty Feebas. Is there something wrong? Did I forget or misunderstand something? My Feebas is also at level 6, so is it a level thing? Thank you in advance. :)