The game binds the player to the slot their controller enumerated on, and the recomp's single profile only answered on slot 0. A pad landing anywhere else made every sign-in query report "not signed in", producing the error. Behind ac6_profile_always_signed_in (default on), profile queries for slots 1-3 now answer with the one profile, so it follows the player to whichever slot their hardware landed on.
Danshet