Related AppleID nightmare. FIL forgot his password & recovery questions and when migrating his iPhone to a new one I did an encryped backup/restore and it resul

Related AppleID nightmare. FIL forgot his password & recovery questions and when migrating his iPhone to a new one I did an encryped backup/restore and it resulted in the new iPhone also getting that broken AppleID. Unfortunately find my iPhone was active on the old one and now the new was was unusable and also could not be reset. Panic... Finally recovered on some old backup his password but without the second factor it was impossible to get full control of the account. So I disabled FindMyIPhone, wiped the phone and set up a new AppleId and restored from a not encrypted backup. Everything worked for a while until the old apps needed updating (Whatsapp...) and the iPhone asked for the password for the Apple Store. Now the new password did not work. Took us ages to figure out that it was asking for the old appleid password - iOS remembers with which account an app was bought but it does not tell you what AppleID it asks the password for when trying to update.