[diggan]

> if you have an unsuccessful unlock first and then you enter the code to unlock, then the phone may train the faceID with the new face too

Ay wat? That sounds completely backwards, like if an incorrect password for account login would automatically reset the account password to the incorrect one, how would that make sense?!

[LexGray]

Worked that way from FaceID introduction. Apple never cared enough. If you share your phone it is on you that the phone accepts the face who you share it with after you enter a pin. It really should have a new face button under the pin.