Need help on unlocking testify

I'm currently trying to unlock testify BYD but stuck on the 2nd prerequisite.

AFAIK, I need to put every non collab Tairitsu on favorite, equip one of them and complete a track that has only her on the main jacket.

I've put every tairitsu on favorites (except the collab and the ones provided by purchasing albums) and played Iconoclast with Tairitsu equipped yet nothing happened.

Am I missing sth???