Hey,
So i sent my buddy a recruit message to give this game a try. He's on a PS4 though, but is having issues logging in. He made his account, he downloaded the game, but when he attempts to log in he gets hit with invalid password. He linked his SE account with his PSN. He can login to the Mog Station and the Square Enix page...yet when he attempts to login to the game on his PS4

Incorrect password.

Are we missing a step? all my other friends played on PC and had no issue logging in. Is there something different with the PS4?